DEPAKTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, DIRECTOR

BTJIiIiETIN 615

RHODE ISLAND COAL

BY

GEORGE H. ASHLEY

WASHINGTON

GOVERNMENT PRINTING OFFICE 

1915
.a.
CONTENTS.

Page.

Introduction............................................................... 5

^ History of development and use of Rhode Island coal ....................... 7

Early history.......................................................... 7

Development from 1840 to 1880........................................ 9

^j Recent history......................................... j............... 11

Development in 1913................................................... 14

>-v Conditions affecting method and cost of mining.............................. 14

' Character of the coal...................................................... 17

i General features...................'.................................... 17

Field conditions...................................................... 17

Physical appearance................................................... 20

Specific gravity....................................................... 21

Chemical character.................................................... 23

-n Reason for low heat value of Rhode Island coal......................... 33

Behavior of Rhode Island coal toward moisture ......................... 37

^ Utilization of Rhode Island coal............................................ 38

1 Kinds of use.......................................................... 38

Household use......................................................... 39

Use in steam raising. ..................................................... 41

Use in metallurgy...................................................... 46

Briquetting tests...................................................... 47

Brick burning and similar work......................................... 48

Indirect use as water gas or producer gas................................. 49

Use for foundry facings and furnace linings.............................. 57

Conclusions............................................................... 57

Papers and reports......................................................... 58

Index.......................................................:............ 60

ILLUSTRATIONS.

PLATE I. Sketch map of the Rhode Island coal field........................ 6

II. Views at Budlong mine, Cranston, R. I.: A, Open cut in mine, looking north; B, Face of bed a little north of the mouth of the slope, 

showing the characteristic schistose or squeezed-lens appearance 

of the coal.................................................... 12

III. A, Surface plant at Budlong mine, Cranston, R. I.; B, Surface plant

at South mine of Portsmouth Coal Co., Portsmouth, R. I......... 13

IV. A, View in graphite mine at Fenners Ledge, near Providence, R. I.;

B, Diagram showing distortion of the bed represented in A...... 18

V. A, View at north end of Budlong pit, Cranston, R. I.; B, Diagram 

showing variations in thickness of anthracite at north end of Budlong pit, represented in A..................................... 19

FIGUHE 1. Crushed structure of coal........................................ 19

2. Chart showing composition and theoretic heating power of Rhode 

Island coal in comparison with other coals with which it must 

compete in New England..................................... 24

3. Chart showing relation of carbon in Rhode Island coal to fuel value.. 36

3

EHODE ISLAND COAL.

By GEOEGE H. ASHLEY.

INTRODUCTION.

Rhode Island coal has had a perennial interest for the people of that 

State and for outside coal and iron men and promoters. Its situation, 

directly on the seaboard and in the center of a region of dense population and large manufactures (see PL I), gives it a great advantage 

in the New England markets over other coals through reduced cost of 

transportation, an item that adds largely to the cost of the coals with 

which New England is now supplied. Lured by this apparent advantage, company after company has sought to exploit the coal or to 

utilize it in metallurgic enterprises in which they were interested; 

but the fact remains that Rhode Island anthracite is still unused commercially and the impression has become general that, considered as a 

source of heat, it is more of a will-o'-the-wisp than a reality.

On the one hand, it is contended that in the final great conflagration Rhode Island coal will be the last thing to take fire. On the 

other hand, it is said that for more than 20 years the Taunton Copper 

Co. used this coal exclusively and successfully for fuel. Both these 

statements can not be correct, so to meet the demand arising from 

many inquiries made of the Survey for some definite statement of 

facts in regard to Rhode Island coal, the author spent a few days in 

the first part of October, 1913, in Rhode Island studying the mining 

and use of the coal, and by means of the results of those studies and 

other data, already published, has prepared the following brief paper 

describing the coal, its use, and its mining. The geology of the Rhode 

Island coal field, at least of that part of it which is in Rhode Island, 

will be described in a detailed State report, now in preparation by 

Charles W. Brown, State geologist of Rhode Island.

The facts ascertained and here reported may be briefly summed up 

as follows:

The coal of Rhode Island is extremely variable in character and quality, ranging from anthracite to graphite, and containing moderately 

high ash to very high ash, and usually a high percentage of moisture 

when first mined. Because of its peculiar characteristics, all the coal 

requires peculiar handling to be used successfully, and the extremely

5
6 RHODE ISLAND COAL.

4

graphitic portions can hardly be used as fuel. The attempt to burn it 

or to treat it as other coals have been treated has usually been unsuccessful, but if properly prepared and properly used, it appears to have 

possible uses. Its high content of water requires that it be seasoned 

under cover before it is used, and its commonly high content of ash 

is adverse to its shipment for use at distant points. Its greatest future u 

use, therefore, appears to be at the mines in the manner indicated in ~x 

this report. r'

The coal beds appear to have been originally of moderate thickness, U 

but they have been folded, compressed, and squeezed by pressure 

until the coal has been forced into great pockets in places and nearly 

or quite squeezed out elsewhere, the beds as a whole dipping into the ^ 

earth irregularly and at high angles. On account of this folding and 

internal movement the coal has itself been broken, compressed, ^ 

twisted, and squeezed, as putty may be squeezed through the fingers, . r 

and in places there have been introduced into it large quantities of 

quartz and other rock impurities. Mining will be cheap in the pockets 

and expensive where the coal is thin, the net cost of mining probably 

running considerably higher than in the anthracite field of Pennsylvania. The possibility of using the associated clay rock for making 

paving brick, tile, and like products suggests itself, and such use may x^. 

materially offset a part of the cost of mining in certain localities.

The apparent failures to mine the coal profitably appear to be due 

to four causes first, improper preparation of the coal at the mines; 

second, attempted use in and with furnaces and with apparatus built 

for use of dissimilar coals; third, relatively low duty obtainable from > 

the coal in comparison with competing coals per dollar of cost, and 

the special and particular handling required; and, fourth, stock jobbing. The attempt, for example, to burn Cranston coal in large '~ 

sizes, fresh from the mine, in an ordinary furnace is doomed to disappointment. The attempt to pay dividends on a capitalization of 

several million dollars from the profits on a daily output of a few >* 

hundred tons of coal, improperly prepared and improperly used, can 

have but one end.

Rhode Island coal needs investigation rather than investment. '*" 

Though it presents a field of peculiar interest to the practical coal 

operator who commands sufficient funds, with the possibility of successful use on the spot in making power by modern methods with r 

financial reward, its use as a basis of general stock selling is open to a. 

the gravest suspicion, and such stock should be avoided by nontechnical investors until the property represented has been examined "~ 

for them by competent experts.

The attempt to sell Rhode Island coal in the open market under 

present conditions is almost certain to result in failure. The public V 

at large has lost faith in this coal as compared with other coals used
U. S. GEOLOGICAL SURVEY BULLETIN 615 PLATE I

i^Bridpewater

LEGEND

Carboniferous rocks

Pre-Carboniferous rocks

Coal mine, anfhracite or graphite

Abandoned mine or prospect

Slrike and dip

SKETCH MAP OF THE RHODE ISLAND COAL FIELD.
DEVELOPMENT AND USE OF THE COAL. 7

in New England, partly because of its weight, making it appear small 

in bulk when delivered, partly because of the excessive amount of 

ash carried by most of it, but mainly because of the lower duty it 

usually renders when burned in the ordinary way. On the other 

hand, the sale of Rhode Island coal as electricity, ready for use by 

the turn of a switch, will avoid any possible prejudice or any failure 

because of improper use, and will avoid freight charges on the ash. 

Such use, therefore, possibly through the medium of the gas producer and gas engine, seems to be the proper aim of future successful 

exploitation. This use means a few plants specially built and specially manned. So utilized, it is believed that Rhode Island coal 

may afford a large field of profitable investment.

HISTORY OF DEVELOPMENT AND USE OF RHODE 

ISLAND COAL. 1

EABLY HISTORY.

In studying the utilization of Rhode Island coal it is well to review 

the successes and failures of the past and then to learn, by experimental tests, possible methods of using not yet tried commercially. 

' The "front" bed of coal at Portsmouth outcrops in plain sight in 

the low cliffs bordering Narragansett Bay on the west side of the 

island of Rhode Island, and beds of coal or carbonaceous shale have 

been encountered in digging wells in many places in Rhode Island 

and the adjoining part of Massachusetts, so that the presence of coal 

in the State has been known from a very early time. The coal at 

Portsmouth seems to have been known at least as early as 17.60. In 

February, 1768, patent was granted to parties who "were about to 

dig after pit coal or sea coal" in the hill at the back of the town of 

Providence, as shown by the acts and resolves of the Rhode Island 

General Assembly.

It is said that during the Revolutionary War the British soldiers 

in Newport used the coal from the island for heating. In an address 

in June, 1887, former Gov. Lippett said that his grandfather had 

attempted to' mine Rhode Island coal more than a century before 

that is, prior to 1787.

In 1808 the General Assembly of Rhode Island granted a lottery 

to raise $10,000 in search of coal, and in that year two mines appear 

to have been opened on Butts HiJl, in Portsmouth, one known first 

as the Aquidneck mine and later as the New England mine, and the 

other, on the east side of the hill, known as the Case mine. These 

mines were opened by Purton Nichols, who bought the land but was 

to give the old owner 1 bushel of coal for each 100 bushels mined.

1 This history has been culled from all available sources, especially the earlier geologic reports elsewhere 

referred to and the flies of the Providence Journal.
8 RHODE ISLAND COAL.

In 1809 the Rhode Island Coal Co. and the Aquidneck Coal Co. were 

incorporated, and from $12; 000 to $15,000 was then expended in 

exploiting the coal. In 1812 the general assembly granted a lottery ^ 

of $40,000 to the Rhode Island Coal Co., one of $30,000 to the Aquidneck Coal Co., and one of $12,000 "for the search for coal in Cumberland." Little money appears to have been raised by the granting of ,w 

these lotteries, as Massachusetts refused to permit the sale of tickets 

in that State. According to a letter of Mr. Clowes (1828), these 

.companies failed for want of practical skill and proper preparation \ 

of the coal, the effort being made to market it in large lumps. In 

the early history of the mines "round" coal is reported to have sold 

for $5 a ton and slack for $2.50. Prices were soon reduced to $3 for 

round and 50 cents to $1 for slack coal.

Coal was found in Cumberland in 1808 in digging a well near the r 

house of Timothy Dexter, between Blackstone River and Abbotts r, 

Run, a little north of Pawtucket. Some drilling was done and a pit 

was sunk 80 feet to a bed said to have been 15 feet thick. Several 

hundred tons of coal were raised. >

V

Some was given away, some waa sold, and some used on the premises and in Providence and other towns. * * * But few people knew how to use this anthracite. "" 

They would take it and place it on a common fire and, though it would burn in this 

way, yet'it could not be so used to much advantage. Wood * * * was then 

abundant, and there was no encouragement to working mines when other fuel was 

plentiful, * * * so we did not consider it worth our while to continue the working of the beds. 1

In 1828 interest revived and a new opening 60 feet deep was made 

to the coal. About 50 tons had been taken out when a fall of the 

roof killed the son of the proprietor and led to the abandonment of 

the mine.

In 1835 J. Alexander and Seth Mason & Bros, became interested 

at this locality and sunk a shaft to a depth of 40 feet, when, after a 

heavy rain, the shaft caved in. They then sunk a second slope to a 

depth of 45 or 50 feet, when their funds ran out and they found it 

necessary to incorporate; so in 1836 they incorporated as the New 

England Coal Mining Co. The slope was then continued down the ,_ 

coal bed to 78 feet, and machinery was set up. Drifts were then 

driven 300 feet on the coal and 600 tons of coal was raised, " the last 

of which sold readily for $6 cash at the mine." The coal did not find 

favor, because, it is thought, it came from too near the outcrop and 

was not properly cleaned. About $1,500 worth of coal was sold. 

About this time the surface buildings were burned.

In 1837 more money was raised by assessment and a 150-foot vertical shaft was started. At 60 feet the shaft was abandoned and, as a

1 Hearing on the memorial of the New England Coal Mining Co. before the select special committee of ^»- 

the General "Assembly of Rhode Island and Providence Plantations, together with the report of the 

committee, 1838.
"DEVELOPMENT AND USE OP THE C0AL. 0

last resort, the company, having expended about $20,000, petitioned 

the legislature for financial aid. The mine was worked under a 

25-year lease, with a ground rental of $1,500 a year and a royalty of 

50 cents a ton. The memorial made to the legislature is filled with 

certificates as to the good quality of the coal, but the legislature made 

no appropriation.

After the failure of the two companies at Portsmouth others tried 

to work the mines without success. In 1827 it is reported that 2,200 

tons were raised by 20 men and 5 boys, and sold at $4.50 a ton.

Coal was known in Mansfield, Mass., in 1810. In 1835 three companies, advised and assisted by Dr. C. T. Jackson, were formed for 

mining the coal in Mansfield, namely, the Massachusetts Mining Co., 

at the Harden farm, 2 miles southwest of Mansfield; the Mansfield 

Mining Co.; and the Mansfield Coal Co. The Massachusetts Mining 

Co. expended somewhat less than $15,000 and raised 1,200 to 1,500 

tons of coal, worth from $5,000 to $6,000. All these mines had 

stopped work in 1838. One of the companies is said to have raised 

about 2,000 tons of coal. The mine on the Alfred Harden place is 

described by Jackson as 64 feet deep, with a gallery 40 feet long extending southeastward. Another, on the Otis Skinner place, half 

a mile to the northwest, was 85 feet deep and was equipped with a 

good engine. The third mine, on the Harris estate, was sunk to a 

depth of 100 feet and drifts were cut north-northwest and south-southeast. Jackson reports that the coal cost about c$l a ton to extract, 

the mines raising 10 tons of coal on some days and hardly any on 

other days.

In 1840 it was estimated that about $40,000 had been expended at 

Portsmouth.

Perpendicular shafts and horizontal galleries were excavated and 

a steam engine with an endless chain was used in getting out the 

water, the extra power being used to raise the coal.

DEVELOPMENT PROM 1840 TO 1880.

In 1840 the Rhode Island Coal Co. took over the Portsmouth' 

property after some preliminary drilling had been done by a Mr. 

Spiker. Mr. Otis Peters was connected with this company. His 

mine was deepened from 100 to 400 or 500 feet. Three years later 

the property passed to a Hartford company, which, in turn, failed 

to make it successful.

In 1847 the Portsmouth Coal Co. reopened the old Case mine, on 

the east side of Butts Hill, but soon abandoned the enterprise. At 

that time the mine on the west side of the hill was being run by the 

Aquidneck Coal Co. In the last half of 1850 this mine yielded 3,100 

tons of coal.
10 RHODE ISLAND COAL.

In 1850 the Mount Hope Mining Co. took the old Case mine, giving 

it the name Mount Hope mine. Dr. Hartshorn, of Providence, and 

Gov. Jackson, of Rhode Island, were among the owners. About the 

same time a mine was opened in Bristol. The Aquidneck Coal Co., 

working on the west side of the hill, deepened their mine from 150 

feet down the slope to 625 feet. In 1852 they were employing 55 

men and raising 75 to 100 tons a day, using two 40-horsepower steam 

engines for pumping, hoisting, screening, and assorting the coal for 

market. The cost of mining was then estimated to be $1 a ton.

This company tried hard to induce the use of the coal by large 

manufacturing plants, going so far as to send a man, John Corrigan, 

to manufacturers to show them how to use it. For a time, apparently, 

a considerable trade was built up, but it was found that when the coal 

was used by the regular firemen the furnace walls were melted, and, 

as a whole, the great care required in its use was too much of a burden, 

so people refused to use it. The company lasted three years, and 

the mines were then taken over by a Worcester company, which ran 

for a few years and sold out to the Taunton Copper Co.

The Taunton Copper Co. is the one shining example of continued 

successful use of Rhode Island coal. This company opened the 

North mine before 1860 and continued operating until 1883, building 

a dock and railroad connections. Though most of the coal used came 

from the North mine, the South mine was extended from 700 or 800 

feet to 1,600 feet. A copper smelter was built and coppe' ore was 

brought in from Cuba and South America and smelted. This company, of which Mr. S. L. Crocker, of Taunton, was president, mined 

about 10,000 tons of coal a year. The coal was also used to some 

extent for domestic purposes and at least "several cargoes" were 

shipped to Poughkeepsie, where they were used successfully in the 

furnaces of the Poughkeepsie Iron Co. The imposition of a high 

protective tariff on copper ores and the death of the principal owner 

of the plant resulted in its closing.

Meanwhile, the Pocasset Coal Co. had opened up the Cranston coal. 

In 1866 Heald, Britton & Ford, of Worcester, wrote that they had 

used some of the Cranston coal; that they were satisfied with it and 

thought it improved the strength of the iron. In 1868 the agent for 

the Pocasset Coal & Iron Co. stated that during his agency 3,600 tons 

of coal had been mined and teamed from Cranston to Providence.1 

In order to introduce it, it was sold under the price of Pennsylvania 

coal and is said to have been used largely by the Mount Hope Iron 

Works, G. G. Hicks Boiler Works, and other establishments.

In 1874 a careful test of Cranston coal was made at the Sockanosset pumping station of the Providence Waterworks. (See pp. 42-43.)

1 Memorial of T. S. Riclgway in relation to the coal field of Rhode Island, presented to the General 

Assembly, 1870. 
_J DEVELOPMENT AND USE OP THE COAL. 11

--,/ The test does not seem to have led to the use of Cranston coal by the 

city and apparently mining was abandoned except in a very small 

, , way. A Mr. Moore at this time used the product of a small mine in 

his facing works at Elmwood.

During this period both the Valley Falls mine and the Roger

, __> Williams mine, a mile to the north, were in operation part of the

time. In 1853, according to Mr. E. T. Hitchcock, the Roger Williams

mins, which had been worked at an earlier date, had been recently

~_. reopened by a 300-foot vertical shaft. From this a drift 260 feet

long had been run, striking a bed from 15 to 25 feet thick. It was

thought by Mr. Hitchcock that this bed was probably a pocket, and

the fact that it was not worked very long sustained that impression.

The Valley Falls mine was at that time being worked by the

"^ Blackstone Coal Co. The mine consisted of an incline 500 feet long,

^ -, reaching to a depth of 375 feet and working on a coal bed 6 to 8 feet

) thick. It is said that four other beds were found at that point.

Hitchcock said that the coal burned well, though in its most recent

- history the Valley Falls mine is reported to have mined chiefly 

material for furnace linings.

RECENT HISTORY.

In 1885 the New York Carbon Iron Co., of Pittsburgh, became interested in Cranston coal. They were then using a patent process, 

in vented by Dr. C. J. Eames, for making billets for blooms. In 1886 

then* metallurgist, Richard Eames, was sent to Cranston to supervise

-^ the opening of a mine and the shipment of coal. He found that the

mine on the Harris place consisted of an open cut with a slope 225

feet long and 40 feet deep. He opened a shaft 75 feet deep and

 > equipped it with buckets capable of raising 30 tons a day. From the

}. bottom of the shaft five chambers were opened, four of them being 40

feet square and the fifth 95 feet long, 15 feet wide, and 20 feet high.

-^ They employed 30 men, and for a time in 1887 shipped to Pittsburgh

u. 250 to 300 tons of coal a week. This was certainly "shipping coals to

Newcastle," but the company seems to have found its use successful

^ and economical. No record was found showing how long this use

of the coal continued, but apparently it did "not last long.

In 1887 W. F. Durfee, of New York, became interested in the estabH, lishment of a blast furnace at Portsmouth for working the Cumberland

J, iron ore. For a time he stirred up considerable public interest. In

an address before the board of trade, June 7, 1887, Mr. Durfee quoted

Prof. R. H. Thurston as approving the use of Rhode Island coal in the

smelting of copper ore and in modern high smelting furnaces. He

\ cited the successful use 'at Pittsburgh, and in the past at Pough-

- keepsie, quoted favorable extracts from letters from other users, and 

suggested its possible future use in the manufacture of fuel (water)
12 EHODE ISLAND COAL.

gas. Possibly as a result of this agitation, in 1889 the Worcester 

Steel Works, of Worcester, Mass., reopened the three mines at Portsmouth, which had been idle since 1883 and which had filled with r~ 

water. This included not only the South and the North, or Crocker, 

mines, but also the Mitchell mine on the west side of Butts Hill, which 

had been opened by Thomas Mitchell in 1871-72 and sunk to a depth 'w. * 

of 80 feet. At the same time Miles Standish, of New York, leased the 

Hazard or Case mine and adjoining property. In May, 1889, 70 

miners were employed, though the mine was still being pumped out. >-~ 

At that time the company expected to employ 300 men as soon as the 

mine had been completely unwatered. It was also the intention to 

erect a blast furnace and foundry at Portsmouth and mine Cumber- y 

land iron ore. The project was not successful and the property 

reverted to the Eice heirs, of Boston, and remained idle for 20 years, 

or until 1909. /- , Meanwhile, attempts were made to mine the coal at Cranston, ( 

usually by stock companies. It is reported that not less than seven 

companies were so formed during recent years. These companies may ^ 

be typified by the Cranston Coal Co., which was active two or three 

years ago. This company was organized with a capital of 1,000,000 

shares, having a par value of $5, and the coal was offered at $5 a 

ton, as against $6.50 to $7.50 for Pennsylvania anthracite. Halftone photographs in then1 advertisements show work being carried on 

in an open cut, which has much the same appearance as the cut has 

to-day. A rough estimate indicates that in all of the years this mine 

has been opened not more than 10,000 to 15,000 tons could have been ^ 

removed, so apparently a very small amount of coal could have been 

mined and sold by this company.

When visited by the writer in October, 1913, the Cranston mines ^" 

consisted still of an open cut about 300 feet long and a slope, then full > 

of water, less than 100 feet long, from which rooms had been turned 

off. A dozen men were getting out about 60 tons of coal, which was 't~ 

being hand screened after crushing into small sizes for domestic use j. 

by Mr. Budlong and families in neighboring houses. The coal was 

being mined by drilling and blasting, as rubble is quarried; it was '"" 

then loaded into buckets and placed on cars, which were pushed by 

hand a short distance, then raised from the cut by a derrick. The 

coal next went to a crusher and was then screened. When the mine h 

was visited the coal was being rescreened by hand and bagged. -v. 

Plate II, A, shows the open cut and Plate II, B, a closer view of part 

of the face of the coal at Budlong mine, Cranston, R. I.; Plate III, A, 

shows the surface plant; and Plate V, A (p. 19), shows the north end 

of the mine accompanied by a diagram, Plate V, B, that indicates , 

the coal and its variations in thickness within a few feet, f '--,
U. S. GEOLOGICAL SURVEY BUL1 ETIN 615 PLATE I

A. OPEN CUT IN MINE, LOOKING NORTH.

Mouth of slope with part of incline tre. k in center. Blast going off just to the right. Dip of bed is shown by 

base of overlying rock in lower right corner.

S. FACE OF BED A LITTLE NORTH OF THE MOUTH OF THE SLOPE, SHOWING THE CHARACTERISTIC SCHISTOSE OR SQUEEZED-LENS APPEARANCE OF THE COAL.

. ' VIEWS AT BUDLONG MINE, CRANSTON, R. I. '
U. S. GEOLOGICAL SURVEY ULLETIN 615 PLATE III

A. SURFACE PLANT AT BUDLONG MINE, CRANSTON, R. I. 

A pile of hand-screened coal is seen in the foreground.

B. SURFACE PLANT AT SOUTH MINE OF PORTSMOUTH COAL CO,, PORTSMOUTH, R, ].
DEVELOPMENT AND USE OF THE COAL. 13

In 1898 Boston parties, under the title "Compressed Coal Co.," 

took hold of the Portsmouth mine and put in a briquetting plant. 

The plant, part of which had been moved from Arkansas, made egg 

briquets, using the Zwoyer process. Most of the material briquetted 

was taken from the old culm pile at the North mine and consequently 

was high in ash. The briquets did not find a ready market, the 

attempt appears to have shared the common fate, and the mines 

were again allowed to fill with water.

While this small development was going on at Cranston a new and 

much larger development was taking place at Portsmouth. Sometime previous to 1909 Mr. J. W. Dennis became interested in a process 

of briquetting that was patented by N. W. Bloss, by which Chile 

saltpeter is used to aid in the burning of the coal. Dennis experimented with this process and afterward with a process patented by 

H. J. Williams, of Boston. In the Williams process crude calcium 

chloride is used, as it cost only 1-| cents a ton for the treatment, as 

against 12 cents for the saltpeter. The coal was treated by immersion in a solution of calcium chloride. It was contended by Mr. 

Williams that, whereas the raw coal kindled with difficulty and gave 

a flame only 5 to 8 inches long, which soon disappeared, the treated 

coal gave a flame 36 inches long for an hour and a half, after which 

it gradually decreased but remained long for several hours; that it 

kindled more rapidly and gave a hotter fire. It is said that after 

three years of practical tests and demonstration the method was 

submitted to H. M. Whitney, resulting in the formation, in February, 1909, of the Rhode Island Coal Co., with a capitalization of 

$5,000,000, the company being incorporated in Maine. The company purchased 400 acres and obtained control of the coal rights of 

4,000 additional acres. During the spring and summer of 1909 the 

mine was pumped out, the slope entrance was enlarged and straightened, and the mine was cleaned up. Ultimately the South mine was 

equipped with a breaker, air compressors, large hoisting engines, a 

briquetting machine, and other appliances. (See PI. Ill, B.} The 

coal dust was briquetted by the R. A. Zwoyer process, Mr. Zwoyer being 

employed as the briquetting engineer. The slope was extended to 

2,100 feet, on the same average dip of 31°, to the bottom, though the 

dip became steeper toward the bottom rather than flatter. Pumps 

were put in, the walls at the mouth of the mine were cemented up, 

and the whole mine apparently was put in good condition for work. 

Additional-core drilling was done and the success and future of the 

new enterprise was told in glowing terms in full-page descriptions in 

the daily papers. Estimates were made that the output would be 

4,000 to 5,000 tons a day, at a net profit of $2.50 to $3 a ton. This 

would have yielded from $200,000 to $300,000 net profit each month. 

By December, 1911, the gross receipts are reported to have reached
14 RHODE ISLAND COAL.

( s 

q

$12,175 for the month. In February, 1912, the company went into 

the hands of a receiver. At the time the mine was visited by delegates of the Providence.Association of Mechanical Engineers, May 20, ^ 

1911, there were reported to be 82 miners employed, earning from $6 

to $7 per week, at the rate of $1.50 a car. The mine was then using 

14 mules underground. Later the company was reorganized as the ,^ 

Portsmouth Coal Co. On December 31, 1912, the published report \ 

of the company's finances showed accounts and notes payable 

exceeding the cash and other assets by more than $75,000, and in 

January, 1913, after the receipt of the experts' report, the directors 

of the company advised the stockholders that the mine had been 

abandoned. The pumps were kept going until July, 1913, but when 

visited in October the mine had filled up to the 1,400-foot level and 

the water was gradually submerging the pumps and other machinery. ^

DEVELOPMENT IN 1913. ^

In October, 1913, the conditions in Rhode Island with reference 

to mining may be briefly summed up as follows: 4

Three mines were open, two of which were running. At the <j 

Fenner Ledge, near Providence, 3 men, working under Mr. Fenner, 

were getting out about 3 cars of graphite a month, which was selling 

at more than $7 a ton. At the Cranston mine, on the Harris place, 

near the Sockanosset Reservoir and the Reform School, about a 

dozen men were getting out a few tons of coal from an open cut for 

household use. This coal was being hand-screened and bagged. \ 

Bituminous coal was being used under the boilers at the mine. The ^ 

slope was full of water. At Mr. Budlong's nursery a considerable 

quantity of small coal was stored in the open for use during the 

summer, when the duty required of the engines was smaller. During ! ~" 

the winter soft coal was used exclusively. At Portsmouth both 

mines were equipped for raising coal. The South mine was also 

equipped with briquetting machinery, air compressors, and other "* 

 appliances. The mines were well supplied with pumps, mine telephones, and other equipment, but were gradually filling with water. 

The graphite mine near Central Falls had not been active for several r 

years and was fallen shut. The graphite deposit near Tiverton was 

not visited and its condition is not known. In January, 1914, it 

was reported to the writer that the mines at Portsmouth were being ^ 

dismantled. J

CONDITIONS AFFECTING METHOD AND COST OF

MINING.

As already stated, the coal beds and the associated rocks have 

been subjected to intense horizontal pressure, so that not only has ^ 

the internal structure of the coal been affected, but the coal beds
METHOD AND COST OF MINING. 15 

" f

and other rocks have been compressed into great folds. Unfortunately for mining, the folding is in many places very complicated. 

i^ The coal, which is relatively soft, has yielded more than the surJ rounding rocks, so that the beds have lost their original regularity 

and now occur in pockets, irregular in size and shape, separated by

*, more or less extensive areas.of thin coal or areas from which the 

; coal has been entirely squeezed out. Furthermore, the varying intensity of the pressure from place to place has also resulted in consider- 

^. able differences in the quality of the coal; in some areas it has been 

converted entirely to graphite with a large admixture of ash; in 

others, where the pressure was less, the percentages of graphite and

 ^ ash are much less or very low.

In view of these conditions it must be recognized that Rhode

^ Island coal can not be mined on a large scale according to a regular

.i plan, as most coal may be. Such mining, like most metal mining,

will face uncertainties as to the position, the quantity, and the

quality of the mineral sought. These uncertainties will probably be

greater in some parts of the field than in others. In flat-lying regular

beds of coal 5 to 8 feet thick practically all the digging is in coal

and all the product may be sold. The mine may be laid out in

^ regular entries at regular distances apart, from which rooms of equal

'-. length are turned off at regular intervals and the intervening pillars

" so mined out that, ideally, no coal is left in the mine. Furthermore,

haulage is a simple matter, as the motors may be taken into the

rooms or shifted to any part of the mine without difficulty.

^fR. By contrast, in the Rhode Island coal field extensive prospecting

; will be necessary to determine the location of the lenses of workable

coal. The mine must be developed along the irregular lines deter-

 i mined by the lenses, and a considerable portion of the digging will

be hi rock, as where the coal is thin, or where it may be necessary to

diverge from the bed in order to keep the haulage ways on fairly even

-K grade. This rock digging costs as much as or more than the digging in the coal and does not yield a salable product. As the shape 

and position of the lenses of thicker coal can not be known until the

v coal is mined out, it will not be possible to plan entries and rooms 

so as to remove the coal at the least possible cost.

To these special costs, due to the irregularity of the beds, must be

^ added the usual higher cost of mining by slope or shaft as compared

,1 with drift mining and the higher cost of mining and haulage hi 

highly pitching beds as compared with flat-lying beds. These and 

many other elements of cost may not differ greatly from similar 

costs in the anthracite fields of Pennsylvania or in small areas in 

other fields of the United States, provided that the coal at any place

X maintains a fairly" uniform dip, as it does at Portsmouth, and fairly 

uniform thickness, which will probably not be found in any part of
16 RHODE ISLAND COAL.

this field. If, however, the coal bed is crumpled into S-shaped

curves, or other curves of fantastic shape, as the surface indications

in some areas suggest, the cost of removing the coal may be greatly ^-?

increased.

The cheapest coal bed to mine has a thickness of 6 to 8 feet. Where 

the beds run under 6 feet, the cost begins to rise, at first slowly, but ^ v 

more and more rapidly as the thickness decreases. For equal areas, : 

a 3-foot bed yields only half the tonnage of a 6-foot bed, but involves 

for the same tonnage of yield the care of double the amount of roof ^-' 

and the laying of double trackage, besides the additional cost of 

supervision and many other items. The mining rate usually begins 

to increase rapidly as the thickness of the coal goes below 3 feet, ^ 

and as the decrease continues the proportion of rock that must be , 

mined and paid for without return steadily increases, so that for /T' 

beds from 1 foot to 18 inches in thickness the cost per ton may be ^ 

two or three times the cost of a bed from 3 to 6 feet thick. On the 

other hand, experience has shown that under usual conditions the 

cost of mining per unit of output does not continue to decrease as 

the bed increases in thickness beyond the zone of minimum cost, 

for what is saved in trackage and other items is more than made up 

in the increased cost of timbering or decrease in percentage of ~ 

recovery.

If the shale or clay lying next to the bed of coal can be used commercially it may be mined with the coal and thus the cost per ton for 

mining the coal may be greatly reduced. In studying this field, 

therefore, attention should be given to the character of the shale or *" 

clay adjoining the coal. The writer would suggest that the shale v 

accompanying the coal at Portsmouth be tested for use in the manufacture of paving brick and draintile. r"

Another element to be considered is the uncertainty of the extent 

of the beds or of their persistence in character. This field has not 

yet been sufficiently explored to show whether the beds are extensive ^ 

or whether they were originally laid down in small basins. As this > 

matter is being studied by the State survey, under Mr. Brown, the 

writer did not make a detailed examination of the coal beds, such as ^ 

would be necessary to discriminate between differences of thickness 

due to pressure from those due to the differences of original deposition 

of the bed. The mining at Portsmouth strengthens the belief that < ** 

the beds there may at first have been very regular, though mining ! - 

and prospecting have not yet been extensive enough to indicate 

whether the Portsmouth area is more than a local basin. On the 

other hand, a comparison of the sections at the Sockanosset mine 

with those at Fenners Ledge suggests variability in quality if not in 

extent. ^
CHARACTER OF THE COAL. 17

In view of the conditions mentioned, it is evident that mining on 

an extensive scale in Rhode Island should not be undertaken until 

the field to be mined has been thoroughly and completely tested by 

the diamond or core drill. A hole should be drilled in each 10 acres 

or smaller area and the coal cores analyzed. The fact that once or 

twice extensive drilling of this kind has been carried on in this field 

and was not followed by an attempt at development indicates that 

the results were not all that might have been hoped for. Thus the 

Portsmouth field was drilled across by Mr. A. B. Emmons in 1883-84, 

but the results did not lead to development.

At present the only mine that might furnish data as to cost is that 

at Portsmouth. The coal at Sockanosset has been mined either in 

open cut by ordinary quarry methods or by shallow slopes, neither of 

which can afford data for computing the cost of mining on a large 

scale under existing conditions. Evidence from several sources indicates that the cost will average not less than $2.50 a ton, a figure 

given by Shaler in discussing the subject in 1899 and quoted by the 

superintendent of recent mining operations at Portsmouth. As the 

cost of mining coal tends to increase as the mine workings increase in 

extent, the actual cost of extensive minrng will probably exceed $2.50 

unless it is possible to utilize the shale that lies next to the coal.

CHARACTER OF THE COAL.

GENERAL FEATURES.

Physically and chemically the coal varies greatly from place to 

place, both in the field as a whole and within any one mine. Coal is 

an indefinite mixture of carbon, hydrogen, oxygen, nitrogen, and 

sulphur, and of other materials which do not burn and which are 

grouped together as ash. Carbon is the principal element. In part it 

appears to occur as uncombined carbon, or, as it is commonly called, 

"fixed carbon," and in part it is combined with hydrogen and possibly 

oxygen in different combinations. The oxygen is so combined with 

hydrogen that in the combustion of the coal the oxygen and oneeighth of its weight of hydrogen, if so much is present, passes off as 

moisture without adding to.the heating value of the coal. Small 

quantities of nitrogen, sulphur, and other substances are usually found 

in the coal, besides the ash, which is mainly material that has been 

added to the original vegetable matter and which may range from 1 

or 2 per cent to 50 per cent or more.

FIELD CONDITIONS.

Coal has been derived from vegetable matter which, when buried in 

quantity in the earth and subjected to pressure and heat, undergoes 

changes and gradually loses part of the hydrogen combined with 

97887° Bull. 615 15 2
'18 RHODE ISLAND COAL.

carbon, so that there is a consequent proportional increase in the percentage of uncombined carbon. In the lower grades of bituminous 

coal the uncombined or fixed carbon ranges from 40 to 55 per cent of 

the coal. Where the coal has been subjected to greater pressure or 

heat, the fixed carbon may increase to 65 or even to 75 per cent as in 

semibituminous coals. Where the coal has been subjected not only 

to the pressure of the overlying rocks but has been strongly compressed from the side, so that the beds are folded into great folds, as 

in the anthracite field of Pennsylvania, the fixed carbon may form 

80 or 90 per cent or more of the coal.

In the Rhode Island field the pressure on the sides appears to have 

been still more intense, not only folding the rocks in great folds but 

crushing, squeezing, and shearing them with accompanying heat so 

high that in some places they have been changed chemically and 

physically. As a result of this intense pressure and heat the coal of 

Rhode Island has been changed to anthracite containing a high percentage of fixed carbon, and in places the material of the beds has 

flowed, like so much putty squeezed in the hand, until the original 

structure is practically all lost and all or nearly all traces of the combined carbon and hydrogen have been driven off, so that there the 

material has reached the last stage and become graphite.

In many regions of intense pressure and folding though the harder 

beds of rock may maintain their thickness and character with little 

change, any softer rocks, such as clays or coal, tend to yield, flowing 

away from the points of greatest pressure and accumulating in areas 

of less pressure. In these areas the intensity of pressure varies with 

some degree of regularity, appearing to be greatest at intervals or 

nodes along certain lines and least in other lines, somewhat after the 

manner of waves of water or air. The position of these lines with 

their nodes in any area must be worked out in the field, as the 

causes of this variation are not yet well understood.

In the Rhode Island coal field the coal beds are associated with 

clay rooks that have yielded with the coal beds, though apparently 

not to the same extent. This has allowed a greater variation in the 

position of the coal beds than would otherwise have occurred. As a 

result, the coal instead of forming a string of regular lenses connected 

by areas of thin coal may in places occur in lenses that are extremely 

irregular. Plates IV and V show in outline the type of lenses being 

mined at two points near Cranston.

An'examination of the coal at different points in one of these lenses 

shows a considerable difference in the character of the coal. Wherever there has been a plane or surface in the coal along which considerable sliding has taken place, the coal in that surface appears to 

have been more heated and metamorphosed than the rest, and has
U. S. GEOLOGICAL SURVEY BULLETIN 615 PLATE IV

J.. VIEW IN GRAPHITE MINE AT FENNERS LEDGE, NEAR PROVIDENCE, R. I.

-Schistose 

sandy sha/

B. DIAGRAM SHOWING DISTORTION OF THE BED REPRESENTED IN A.

The bed nearly pinches out above the present workings. The best graphite being mined was found at the right, 

in a sort of tongue squeezed out in the folding of the rocks.
U. S. GEOLOGICAL SURVEY BULLETIN 615 PLATE V

A. VIEW AT NORTH END OF BUDLONG PIT, CRANSTON, R.

. DIAGRAM TO SHOW VARIATIONS IN THICKNESS OF ANTHRACITE AT NORTH END OF 

BUDLONG PIT, SHOWN IN A
CHARACTER OF THE COAL. 19

become graphitic. In places the whole bed has been squeezed until 

it was forced to flow to areas where the pressure was less, and to such 

an extent that all the coal appears to be graphitic. In general, the 

thinner the coal is at any point the larger the percentage of graphite 

it contains, as though internal movement had been greater at those 

points.

It is clear that this compression and movement in the coal has 

been slow, at times breaking the coal so as to leave open crevices 

and then compressing and recementing it. In places where such 

open crevices have been formed temporarily water containing quartz 

hi solution has flowed into the crevices and the quartz has been 

deposited in some places as a network through the coal. Where the 

beds are much metamorphosed, as at Fenners Ledge, a considerable 

quantity of asbestos is associated with the carbonaceous material. 

The crushed structure of the coal is shown in figure 1. The structure 

is well brought out by the minute lenses of _ 

quartz and pyrite.

The breaking open and recementing of the 

coal appears to have permitted the injection 

into it of more or less of the adjoining shale 

rock, so that, in general, where the coal is 

thin from having been squeezed out it is 

much higher in ash than elsewhere, the high 

ash appearing to increase with the increase of FlGUEE i- Crushed structure 

graphite. The coal in the same mine may

therefore vary greatly from place to place, being high in graphite and 

ash in places where as a rule it is thin, and being freer of both ash 

and graphite in the pockets.

The field as a whole appears to have been subjected to large 

regional differences in pressure and there are corresponding regional 

differences in the character of the coal. For example, a comparison 

of the ooal at the Portsmouth mine, which is toward the middle of 

the basin, with the coal and other rocks at places along the edge of 

the basin suggests that in general the coal beds and accompanying 

clay rocks have undergone greater distortion and change at the 

edges of the basin than at points in the center. The pressure in the 

center of the basin appears to have been relieved to some extent by 

the yielding and crushing of the rooks on the edge of the basin, where 

they were compressed against the older, harder rocks.

Unfortunately the coals in most of the ulterior part of the basin 

appear to be buried too deep for mining. Future prospecting may 

reveal increased areas of coal on the arches of anticlines, or in blocks 

brought up by f aulting, that will be within mining distance of the 

surface and yet have the advantage of being less disturbed and 

changed than the beds now known around the edges of the basin.
20. BHODE ISLAND COAL.

PHYSICAL APPEARANCE.

The best coal seen approaches Pennsylvania anthracite in color, 

fracture, and luster. The fracture, however, is less conchoidal and 

the color invariably tends to be more of a steel gray, none of the 

coals seen showing the bright jetlike luster of freshly broken Pennsylvania anthracite. But little difference was noted in the color of 

the best coal from Portsmouth and the best from Cranston, though 

the average coal at Portsmouth differs considerably from that at 

Cranston. In fracture the best coal at Portsmouth tends to break 

down in rhombs with short, irregular faces instead of with the rounded 

conchoidal surfaces of broken anthracite. In some specimens the 

rhombs are closely diamond-shaped in cross section with parallel 

faces. Other specimens of the coal appear to consist of a series of 

irregular plates, as though it had been cleaved by transverse pressure 

and the plates then pushed over each other but finally cemented 

together into a coherent mass. In still other specimens the coal 

appears to have been broken into minute fragments of all shapes, 

which were later recemented and consolidated like a conglomerate 

or breccia. The color of such pieces ranges from steel gray, locally 

slightly bronzed, to a dull black, like the color of manganese. Much 

of this coal, in fact, is dull bluish gray to black, with bright luster in 

spots, grading into black without luster. Though hard, this coal as 

a rule is friable and requires careful handling in shipping to prevent 

slacking.

In the Cranston district the coal everywhere seen differs both in 

appearance and fracture from the Portsmouth coal, the closest resemblance noted, both in color and fracture, being in coal said to 

have come from the foot of the incline at the Budlong mine. As a 

rule the Portsmouth coal appears to have been broken into minute 

fragments by a close network of fracture planes, but the coal at 

Cranston has more of a flow structure, the original rhombic fragments, if there were such fragments, having been pressed and drawn 

into scales or flakes. Pieces of the coal, large of small, everywhere 

present smooth, rounded surfaces, rubbed and polished or glistening. 

These surfaces appear in many specimens to consist of at least a 

film of graphite. Exceptionally, the entire piece appears to be composed of thin scales or flakes of graphite, held together more or less 

imperfectly. Such pieces will make a mark as readily as a pencil, 

and have an oily feeling when rubbed with the fingers. Much of the 

gray appearance appears to be due to films of a grayish or bluishwhite substance, apparently quartz that has been carried into the 

coal in solution in water; and the same solutions also carried in more 

or less pyrite or iron sulphide, the "sulphur" of the miners. In 

places the quartz forms veins or irregular plates an inch or two thick, 

commonly with a lens of pyrite running through the center.
CHARACTER OF THE COAL. 21

The best of the Cranston ooal shows almost no quartz or only in 

minute scattered flakes or films. The poorer ooal looks as if it'had 

been dipped into some gray solution and then dried. The poorest 

coal is full of distinctly visible quartz veins of considerable thickness 

and extent and, where mined near the surface, is commonly stained 

rusty red from the oxidation of the pyrite. In fact, much of the coal 

at Cranston, if picked up beside the road, would not seem to be coal 

nor to have any of the qualities of a fuel. It shows a bluish-gray to 

ashen-gray color, changing in places to a dull or glistening black, and 

has the structure of a foliated schist. Much of this coal would be 

defined bv a geologist as a carbonaceous schist. / o o

SPECIFIC GRAVITY.

The weight or specific gravity of Rhode Island coal has operated 

against its use. Pennsylvania anthracite, as delivered, has a volume 

of 35 to 40 cubic feet per short ton, according as the coal is broken 

large or small. Much of the Rhode Island anthracite in the same 

sizes has a volume of only 25 to 30 cubic feet per ton. The householder who has been accustomed to the ordinary-sized load of Pennsylvania anthracite is inclined to think when he receives a load of 

Rhode Island anthracite that he is getting short measure or to 

believe that the smaller volume of the Rhode Island coal can not give 

as much heat as the larger volume of the Pennsylvania coal. He thus 

at once becomes prejudiced against the coal or the use of it.

The writer had the specific gravity determined of five samples of 

Rhode Island anthracite and one of Pennsylvania anthracite in the 

chemical laboratory of the United States Geological Survey. In 

order to learn to what extent ash affected the specific gravity, C. E. 

Lesher later determined the ash from the same samples. The results 

obtained are as follows:

Specific gravity and ash of Rhode Island coal.

No.

1

?,

3

4

5

Sample. Specific 

gravity.o

1.65

1.96

2.20

2.06

2.45

1.43

Ash.6

13

13

18

6

65

5

Air-drying loss 

at60°C.6

17

3.5

1

.5

1

.5

o Examined by George Steiger. Specimens were first coated with paraffin so that the specific gravity 

obtained would be independent of pore space.

& Determined by C. E. Lesher. Specimens had had ample opportunity to dry out, so that, with one 

exception, there was but slight air-drying loss at 60° C.

A comparison of the figures shows but a slight relation between 

weight and ash. The figures suggest a distinct difference in the 

weight of Cranston coal as compared with that of Portsmouth coal.
22 BHODE ISLAND COAL.

Sample 4, from Cranston, has a higher specific gravity than sample 2, 

from Portsmouth, though it contains less ash. Sample 3 has a 

higher percentage of ash and also higher specific gravity than sample 

4. But samples 1 and 2, with the same percentage of ash, show a 

marked difference in specific gravity. In fact, if the specific gravity 

of sample 1 was obtained while it contained 17 per cent of moisture, 

as it seems to have been, the air-dried sample would have had a 

specific gravity of only 1.36, making the difference still more striking.

The sampling and testing were not complete enough to permit 

general conclusions to be formed with certainty, but the figures suggest, at least, that there may be differences in the specific gravity of 

.the coal regardless of the ash. Sample 1 indicates that some of this 

coal when air-dried is of no higher specific gravity than other 

anthracite coals.

These figures for specific gravity may be supplemented by the 

following figures obtained by Jackson: 1

Specific gravity and ash of coal from Rhode Island and Massachusetts, according to C. T.

Jackson.

Do................................................................................

Specific 

gravity.

1.85

1 7704

1 G9

1.71

1 7Q

Ash.

3.235

9.50

6.4

2.0

4.0

A. B. Emmons 2 obtained 2.209 as the specific gravity of coal from 

the Cranston shaft, and the ash ran 13.07 per cent. The correspondence with the figure 2.20, obtained by Steiger, may be accidental, but it confirms in a measure the recent determination.

In general, it appears that 'Rhode Island coal is heavier for a given 

volume than the coals with which it competes; that the coal on the 

edges of the basin, where most compressed, is heavier than out in the 

basin, as at Portsmouth or Mansfield; -and that, though these differences may be in part due to differences of percentage of ash, they 

appear also to be due to differences in the weight of the coal matter.

Some idea of the bearing of the specific gravity of the coal on its 

burning qualities may be gained from a quotation from a recent work 

by Porter and Durley: 3

It is probable that few, if any, coals which have a specific gravity over 1.6 are worth 

burning and, excepting the anthracites and possibly one or two other special coals, 

a specific gravity of 1.52 may be taken as the approximate density of the most impure 

coals that can be profitably burned for commercial purposes.

1 Jackson, C. T., Report on the geologic and agricultural survey of the State of Rhode Island, Providence, 1840.

2 Emmons, A. B., Notes on the Rhode Island and Massachusetts coals: Am. lust. Min. Eng. Trans., 

vol. 13, pp. 510-517,1885.

3 Porter, J. B., and Durley, R. J., An investigation of the coals of Canada: Canada Dept. Mines, Mines 

Branch, vol. 1, p. 194,1912.
CHARACTER OF THE COAL. 23

CHEMICAL CHARACTER.

The chemical composition of a coal determines its heat-giving 

capacity. The principal heat-giving elements of any coal are the 

uncombined or fixed carbon and the combined hydrogen and carbon, 

known as "volatile matter" or "volatile combustible." If Rhode 

Island coal contained only those substances it would contain about 

95 per cent of fixed carbon and 5 per cent of volatile matter, or in 

the ratio of 19 to 1. Pennsylvania anthracite, as shown by an average analysis of a large number of commercial samples made by the 

Second Geological Survey of that State/ shows an average ratio of 

22 to 1, so that Rhode Island anthracite, when freed of water and ash, 

contains a little more volatile matter and a little less fixed carbon 

than Pennsylvania anthracite. Unfortunately, the percentage of 

moisture and ash in Rhode Island coal greatly exceeds that in Pennsylvania anthracite, with which it comes into competition, and, 

further, as discussed beyond, it is found that the volatile matter of 

Rhode Island coal is entirely noncombustible, consisting probably 

of water and carbon dioxide, so that it should, as a source of heat, 

be excluded from the coal and be grouped with the ash and moisture.

The average analysis of Pennsylvania anthracite referred to gives 

the average percentage of moisture in the commercial coal as 3.30. 

The average of recent analyses of mining samples of Rhode Island 

coals, made by the United States Bureau of Mines, is 16 per cent 

for samples from Portsmouth, where the coal is mined underground, 

and 6.5 per cent from the open cut at Cranston. The ash in the 

average Pennsylvania anthracite analysis is 8.40; in the recent 

analyses of Rhode Island coal by the Bureau of Mines it. ranges from 

13.76 to 33.90, the average being 22.91. In general, it would appear 

that the moisture in fresh Rhode Island coal is from two to six times 

as high as in Pennsylvania anthracite and the ash between two and 

three times as high. The possibility of reducing the moisture by 

drying and the ash by washing will be considered below.

As compared with the bituminous coals that are shipped into New 

England, Rhode Island coal is proportionately lower in "pure coal/' 

that is, coal without water or ash, for, though water and ash form 

from one-fourth to one-half of Rhode Island coal as mined, they 

form only one-tenth to one-twentieth of the bituminous coals from 

the eastern edge of the Appalachian coal field. These are the coals 

that are shipped into New England, but they are the highest grades 

of bituminous coals and do not represent bituminous coals in general. Considered commercially, however, Rhode Island coal should 

necessarily be compared with the coals with which it must compete.

The table on pages 26-27 gives a set of recent analyses by the Bureau 

of Mines of samples of Rhode Island coal taken in the mine, in accordl Second Geol. Survey Pennsylvania Summary Kept., vol. 3, pt. 1,1895.
24 RHODE ISLAND COAL.

ance with, the modern practice of cutting the full width of the worked 

portion of the bed, quartering down to a 2-pound sample, which is 

then hermetically sealed so that the moisture content is preserved

Coal and 

laboratory number

Composition 

Average 

Portsmouth, R. 1. < coal 

Heat value

Composition 

Average 

Cranston, R. 1. 

coal 

Heat value

Composition

1245 

Pa, anthracite culm

Heat value

Composition

AveraRe5953-5956 

Pa. anthracite

Heat value

8488 

Clearfield,-Pa. 

coal 

Heat value

 Composition 

2156 

Cambria Co., Pa. 

coal 

Heat value

Composition 

5456 

Pocahontas, Va. coal 

Heat value

Composition

8112 

New River. W Va. 

coal

Heat value 

Composition, per cent 

B. t u., thousands

| HEAT-Y.ELDING ELEMENTS OF COAL ^*S^S^^§^tNG thermSl

, Fixed carbon 56.4%

Combustible matter 55.6 %^ 

Fixed carbon 

Theoretic yield, B. t u; 8,060 -J

, 'Fixed carbon 68.3%

Combustible matter &l°l°-\ 

Fixed carbon 

Theoretic yield, B. t a: 9,710 V

units 

i vol. found 

mat ., _, 

2.8% Ash 23.5% Moisture 17.1%

Carbon! in volatile 0 % ? Total 55.6% 

Available hydrogen 0% ? 

.10 - Sulphur .34% Total 8,070 8,103

\x Vol. 

imat ' Moisture 

|2.6% 'Ash 22.4% 6.5%

Carbon in volatile 0% ? " Total 67% 

Available hydrogen 0% ? 

^^^10»-Sulphur.38% Total 9.720 9.673

f Fixedcarbon71.7% ^T 'Ashl S.7JF8®

Combustible matter 71.7J5S .Carbon in volatile -^Ikfl Total74.7%. 

Fixed carbon { ^Available hydrogen > , 

Theoretic yield, B. t u.: 10,390 -^ 12Q>,1,280, 30«-Sulphur J74% Total 1 1 820 12 040

f Fixed Carbon 84.3 ^

Combustible matter 80.9%^ 

Fixed carbon 

Theoretic yield, B. t u.: 11,730 ~>

, Fixed carbon 72.*°

Combustible matter 72. 7<>« 

Fixeacarbon 

Theoretic yield, B. t u.: 10,440 *>

; 

Fixed carbon73.%

Combustible matter 73.%^ 

Fixed carbon 

Theoretic yield, B. t u.: 10,580 J

f Fixed carbon 75 .3 °/°

Combustible matter 75.3'5'a. 

Fixed carbon 

Theoretic yield, B.t u.: 10,910-*'

< 

/ Fixed carbon 76.4%

Combustible matter 76A%. 

Rxed carbon 

Theoretic yield, B. t u.: 1 1,086 *?'

0 10 20 30

01234567

 >, m°'; Moisture 

!<\ra.k 2.8% 

! x?: 1 Ash 10.7%

f=ll7% Total 82.6% 

Carbon in volatile 0%/ " ' 

>r Available hydrogen -^ 

,1120, 30 ^Sulphur .77% 1 Total 12.880 12.970

\ Moisture 

1 Ash 2.9% 

Vol. mat 20.5% 46%

10.7% 43% Total 87% 

^Carbon in volatile -" ) \ if ^-Available hydrogen ' 

,1,550, 2,670 ,30-SulDhur| Total 14.690 14.510

/ . Moisture 

. f Ash 35% 

Vol. mat 16.8(K>61 .6% /

7.6% 3.81% ^13184.4% 

, Carbon in volatile -* *i . - -1

,', n. x"Ay§j'ablenydr°8en 'i . 1,100 .2,360 ,3Q^Sulnhurl Total 14070 14^79

v (Moisture' 

\ Ash 1-6% 

Vol. matll7.1%5.8%

, 7.8% 4* Total 87.1% ^Carbon in volatile -» * ' 

/ f Available hydrogen ' i 

1,120 2,480 ,30 SulDhurTotall4.440 -14.672

I Moisture ' 

! -«Ash3.2% 

Vol. matlk5%2.7'?<> 

., 7.6% 4.2«Total 88.2% / Carbon in volatile -^ ». 

t » Available hydrogen J 

1,102 2,653 , 30*-Sulohur Totall4.848 14.760

40 50 60 70 80 90 100

8 9 10 11 12 13 14 15 16

Horizontal scales.

FIGUEE 2. Chart showing composition and .theoretic heating power of Rhode Island coal in comparison 

with other coals with which it must compete in New England.

without change until analyzed. The second table gives analyses of 

Ehode Island coal made by the Bureau of Mines from samples taken 

from carload lots or from large quantities, which were tested at 

the laboratories of the Bureau of Mines in different ways. These
CHARACTER OF THE COAL. 25

\

samples have had opportunity to dry out and so show a much 

smaller percentage of moisture. The sample taken at Portsmouth 

consisted of about 20 tons of "the best that the mine can produce." 

In the third table are given some analyses of samples taken across 

the bed, or from lots of several tons each, by A. B. Emmons, 

and analyzed by F. A. Gooch and B. T. Putnam.1 These analyses differ from those in the first table in that the samples have 

more or less dried out according to the weather at the time the 

analysis was made. The Bureau of Mines analyses are all made on 

the air-dried sample. The fourth table includes some old analyses 

by Jackson.2 They are of interest in that they give analyses of coal 

from the part of the field near Mansfield. The analyses from Portsmouth form a basis for comparison. The fifth table gives a few analyses made by the Bureau of Mines from samples in the anthracite 

field; the fields of Jefferson County, Clearfield County, and Cambria 

County of Pennsylvania; the Pocahontas field of Virginia; and the 

New River field of West Virginia.

The chart given in figure 2 shows the relative character of Rhode 

Island coal in contrast with the coals just mentioned, both as to 

composition and heating power.

In the following tables, under "Kind/' A represents a mine sample 

collected by an inspector of the technologic branch of the United 

States Geological Survey; B, a mine sample collected by a geologist 

of the Survey; and C, a car" sample taken at the fuel-testing plant. 

The form of analysis is denoted by number as follows: 1 represents 

the sample as received; 2, the sample dried at a temperature of 105° 

C.; and 3, the sample free from moisture and ash according to calculation.

1 Emmons, A. B., op. cit. 2 Jackson, C. T., op. citt
Analyses of Rhode Island anthracite by the Bureau of M

Newport County.

Sample.

Laboratory No.

9328.............................:...

9329.................................

9330. ................................

9331.................................

C335. .. .

0336...................:.............

0337.................................

9338.................................

Kind.

B.....

B.....

B.....

B.....

B.....

B.....

B.....

B.....

Condition.

1 

2 

3

l'

2 

3

1 

2 

3

1 

2 

3

1 

2 

3

1 

2 

3

1 

2 

3

1

2 

3

Proximate.

Moisture.

16.80

13.26

23.68

22.92

15.9

16.6

14.1

13.9

Volatile 

matter.

2.30 

2.76 

2.26

2.56 

2.95 

3.78

3.01 

3.94 

6.60

2.78 

3.61 

4.55

2.5 

3.0 

5.0

3.5 

4.0 

7.0

4.0 

4.5 

6.0

2.5 

2.5 

3.5

Fixed 

carbon.

64.43 

77.44 

97.74

65.30 

75.23 

96.22

42.54 

55. 74 

93.40

5S.37 

75.72 

95.45

49.8 

53.3 

95.0

46.0 

55.4 

93.0

61.9 

72.3 

94.0

63.2 

73.8 

96.5

Ash.

16.47 

19.80

18.88 

21.77

30.77 

40.32

15.93 

20.67

31.8 

37.7

33.9 

40.6

20.0 

23.2

20.4 

23.7

Sulphur.

0.59 

.71 

.15

.30. 

.35 

.45

.03 

.04 

.05

.10 

.13 

.16

.12 

.14

.22

.15 

.18 

.30

.09 

.10 

.12

1.34 

1.55 

2.04

o Bur. Mines Bull. 22, pt. 1, pp. 184,185,1

9328. Portsmouth, Portsmouth mine, at Marshalls Landing (heading 1,150 feet south of 

south shaft in 900-foot gallery, 500 feet down vertically). Sample taken by C. W. 

Brown.

9329. Same mine (south slope, on 800-foot level, 1,200 feet south of main slope, "Middle" 

6-foot bed). Sample taken by C. W. Brown.

9330. Same mine (69 feet south of north shaft, 150 feet down vertically, 27^-inch bed, 

weathered). Sample taken by N. C. Dale and J. C. Martin.

9331. Same mine (900 feet north of north shaft, at heading in gallery, 23-inch bed). 

Sample taken by N. C. Dale and J. C. Martin.

9335. Same min

main sl

9336. Same min

level of 

Fisher.

9337. Same min

by C. A

9338. Same min

Fisher.
Providence County.

7769.................................

7770.................................

7771.................................

7772.................................

A.....

A.....

A.....

A.....

1

2

3

1

2

3

1

2

3

1

2

3

9.71

4.51

4.54

7.30

2.60

2.88

4.03

3.46

3.62

5.48

3.01

3.15

3.68

1.69

1.82

3.44

61.98

68.65

59.67

62.49

94.52

78.69

82.44

96.32

73.09

78.85

96.56

25.71

28.47

32.36

33.89

13.76

14.41

17.92

19.33

0.07

.08

.11

.12

.13

.20

.83

.87

1.02

.11

.12

.89

7769 to 7772. Cranston (near Providence), Cranston min

Chemical analyses (car and test samples') of Rhod

Sample.

Test No. a

113 c... ........ .....................

190 <i................................

191 d................................

194 d... .............................

Kind.

C......

C......

C.....

C......

Condition.

1 

2 

3

1 

2 

3

1 

2 

3

1

2 

3

Proximate. t>

Moisture.

2.41

3.70

4.80

11.50

Volatile 

matter.

4.92 

5.04 

6.26

2.11 

2.19 

2.87

2.50 

2.52 

3.45

3.41 

3.85

4.74

Fixed 

carbon.

73.61 

75.43 

93.74

71.45 

74.19 

97.12

69.90 

73.42 

96.54

63.59 

71.85 

88.49

Ash.

19.06 

19.53

. 22.74 

23.61

22.80 

23.95

21.50 

24.29

Sulphur.

0.07 

.07 

.09

.06 

.06 

.OS

.10 

.10 

.13

.59 

.65 

.82

H

a Numbers refer to numbers of tests in producer-gas plant. (See pp. 49-54.)

& Proximate analyses of fuel as fired; ultimate analyses of dry fuel figured from car sample.

113. Cranston (near Providence, R. I.), Cranston mine, pit in outcrop (run of mine).

1
Analyses of anthracite from Portsmouth mine, Rhode Island, by F. A. Gooch and B

Water .............................................................

Ash...............................................................

Ash...............................................................

_ , .. Carbon

Fuel ratio, Volamecombustibl6 . ..................................

1

5.12 

6.49 

71.04 

17.35

100. 00 

.216 

Red.

10.94

2

0.52 

6.31 

76.23 

16.94

100. 00 

.224 

Red.

12.08

3

3.18 

4.43 

75.97 

16.42

100. 00 

.258 

Red.

17.14

a Am. Inst. Min. Eng. Procv vol. 13. p. 511,1885. The following footnote accompaniss these analyses: 

the prevalence of a northwest wind, or dry condition of the atmosphere, though the conditions were not sp

period, or a southwest wind, which in Newport is frequently accompanied by a fog."

1. Bottom of shaft, north side; thickness of seam, 3 feet 11 inches.

2. Bottom of shaft, south side; thickness of seam, 2 feet 7 inches.

3. South side, 50 feet from bottom; thickness of seam, 6 feet.

4. South gallery, 370 feet from bottom, upper three-fourths of 6-foot seam. Analyses 1-4 

are from samples taken across the width of the seam.

5. Average of seven analyses made from samples taken at intervals along the length of 

a 6-foot drill core, cut out of what is known as the "back seam" at about 90 feet 

below the mouth of the Portsmouth mine.

6 and 7. The single analyses of the series of seven mentioned under 5, showing the maximum and minimum percentages of carbon and ash.

8 and 9. Samples taken from two lots of several tons each of freshly mined coal used in 

other experiments.

Analysis of ash 

SiO2 .....

Fe2O3 ....

AhOs.

CaO...

MgO..

MnO..

SO3 ......
CHARACTER OF THE COAL. 29 

Analyses of coals from Portsmouth, R. I., and Mansfield, Mass., by Jacksonfl

Portsmouth, R. I., rusty coal, "best quality" ............................

Portsmouth, R. I., coal, solid, grayish-black, and glossy but not graphitic. .

Do...................................................................

Water 

and 

volatile 

matter.

10.0

7.0

10.5

13.0

fi 9

6.0

6.0

Fixed 

carbon.

84.5

77.0

85.84

77.5

87.4

92.0

90.0

Ash.

5.5

16.0

3.66

9.5 

6.4

2.0

4.0

« Jackson, C. T., op. cit-.

These analyses of Mansfield coal must be interpreted in the light 

of recent analyses of Portsmouth coal. They suggest that the coal 

at Mansfield has a little higher percentage of fixed carbon than that 

at Portsmouth and possibly is more graphitic.

Jackson reports a comparative test for ash of Portsmouth and 

Lackawanna coal by Christopher Rhodes, jr. In the first test 33,477 

pounds of Lackawanna coal yielded 2,566 pounds of ash, or 7.66 

per cent; in the second test 32,344 pounds of the same coal yielded 

2,489 pounds of ash, or 7.69 per cent. On the other hand, 8,705 

pounds of Portsmouth coal yielded 1,332 pounds of ash, or 15.3 per 

cent.
of anthracite and bituminous or semibituminous coals from Penn

Pennsylvania.

County.

Lacka wanna ...............

Schuylkill .................. 

Do..................... 

Do..................... 

Do..................... 

Jefferson ................... 

Clearfield. ..................

Cambria. ...................

Sample.

Laboratory 

No.

1245...

5956... 

5954... 

5955... 

5953... 

5219... 

8488...

2152...

Kind.

c......

A..... 

A..... 

A..... 

A..... 

A..... 

B.1-...

C.....

Condition.

1 

2 

3

4

1 

2 

3

1 

2 

3

1 

2 

3 

1 

2 

3

1 

2 

3 

1 

2 

3

1 

2 

3

4

Proximate.

Moisture.

5.41

2.76

2.80

2.30

3.33

3.56

2.9

3.51

Volatile 

matter.

7.02 

7.42 

8.91

2.48 

2.55 

2.93

" 1.16 

1.19 

1.29

1.54 

1.58 

1.83

3.27 

3.38 

3.73

27.19 

28.19 

29.43

20.5 

21.5 

22.5

16.82 

17.43 

18.72

Fixed 

carbon.

71.79 

75.90 

91.09

82.07 

84.40 

97.07

88.21 

90.75 

98.71

82.77 

84.71 

98.17

84.28 

87.19 

96.27

65.18 

67.59 

70.57

72.0 

73.8

 77.5

73.04 

75.70 

81.28

Ash.

15.78 

16.68

12.69 

13.05

7.83 

8.06

13.39 

13.71

9.12 

9.43

4.07 

4.22

4.6

4.7

6.63 

6.87

Sulphur.

0.74 

.79 

.95

.54 

.56 

.64

.89 

.92 

1.00

1.05 

1.07 

1.24

.60 

.62 

.68

.82 

.85 

.89

.77 

.79 

.83

.94 

.97 

1.05

H

Burrows, J. S., Mine sampling and chemical analyses of coals tested at the United States fuel-te

1245. Scranton, anthracite culm.

5956. Two miles west of Minersville; Phoenix Park mine No. 3,1,300 feet east of opening, 

77-inch cut, Diamond bed.

5954. St. Nicholas; St. Nicholas mine No. 209, Mammoth (middle split) bed, 600 feet 

west of opening, 13J-foot cut.

5955. Same, 1,380 feet west of opening, 106-inch cut.

5953. One mile north of Tower City; West Brookside mine, 300 feet north of opening, 

Lykens bed, No. 5,110-inch cut.

5219. Three mile

mine, Low

8488. One-half m

fault. Low

2152. Ehrenfeld; 

from drift 
Virginia.

Tazewell ................... 5456... C..... 1

2

3

1.63 17.17

17.45

18.56

75. 34 5. 86

5.96

0.75

.76

.81

West Virginia.

5467... A..... 1

2

0

3.22 23.53

24. 31

24.85

71.16

73.53

2.09

2.16

0.57

.59

.80

5456. Pocahontas; Baby Pocahontas mine, Pocahontas bed No. 3, 6,700 feet southwest 

of drift mouth, HSf-inch cut. Run of mine, 4 cars.

5467. Winona; 

entry 1, 
32 RHODE ISLAND COAL.

The fact that Rhode Island coal will part with or take up moisture, 

according as the air is dry or moist, is discussed below. (See p. 37.) 

The coal takes up as much as 15 per cent of moisture if it is exposed 

to dampness or loses most of its moisture if it is exposed to a dry wind 

when broken up fine. The heating value of the coal may therefore 

be said to range between the values given for the coal as mined and 

as air-dried.

As shown by the analyses, Rhode Island coal as mined ranges from 

less than 6,000 to more than 9,000 British thermal units where mined 

underground, and from less than 8,500 to more than 10,000 British 

thermal units if mined in open cuts, where it is possible that the coal 

may have dried out in part. The anthracite culm yields more than 

12,000 British thermal units, and three other samples of anthracite 

as mined yield from 12,500 to 13,350 British thermal units. In 

other words, the anthracite culm shows a theoretic heating power 

double that of the poorest of the Rhode Island samples and one-third 

better than the best from underground, or about one-fifth better than 

the best of the open-cut samples. It would appear that in general 

Rhode Island coal as mined has from 60 to 70 per cent of the heating 

power of the bituminous coals cited, though it ranges both above and 

below these figures. This comparison makes it clear that Rhode 

Island coal, if used as fresh mined in large lumps (which can not dry 

out quickly), will not compare well with other coals, regardless of the 

furnace or other apparatus used. But if comparison is made between 

Rhode Island coal and other coals on the air-dried basis the result 

is not quite so one-sided. The other coals cited carry, as a rule, so 

low a percentage of moisture as mined that drying in air increases 

their heating qualities only a very few hundred British thermal units 

at the outside, whereas the drying out of Rhode Island coal may 

result in an increase of heating capacity of 10 to 20 per cent in the 

coals high in moisture and 2 to 10 per cent in the coal from Cranston.

The average of the British thermal unit determinations 1 on airdried samples of Rhode Island coal is 9,908. If sample 9330, which 

is labeled as "weathered," is left out of account the average is 10,068. 

It may therefore be taken as a fair assumption that, on the air-dried 

basis, Rhode Island coal has a value of 10,000 British thermal units. 

On this basis it may be noted that thoroughly dried Rhode Island 

coal has theoretically about 75 per cent of the heating power of anthracite coal and about 70 per cent of the heating power of the high-grade 

bituminous coals that are brought into New England.

The analyses of Rhode Island coal given above are from samples 

of beds that are mined for coal and, as a rule, are from the better 

parts of these beds. The carbonaceous matter of the coal measures of 

Rhode Island grades from the best of these samples to carbonaceous

i Bur. Mines Bull. 22, pt. 1, pp. 184-185,1913.
CHAEACTER OF THE COAL. 33

shale containing only a very small percentage of carbonaceous matter. 

As already explained, where the beds have been squeezed thin, the 

coal has generally been changed to graphite and is accompanied by a 

high percentage of ash, which consists mainly of quartz, apparently 

deposited by water carrying silica in solution. No analyses of properly averaged samples of the more graphitic portions of the coal beds 

are at hand. The following analyses, however, of samples from Tenners Ledge, at Arlington, will give a fair idea of the composition of 

the graphite beds:

Analyses of graphite of Fenners Ledge, at Cranston-, R. I.a

Silica. , ...................................

Volatile...................................

Ash........:..............................

16

47.68

46.32

6.00

100. 00

26

55.04

41.65

2.66

.65

100. 00

36

57.17

39.63

2.63

.57

100.00

46

64.21

34.08

1.31

.40

100.00

5

25.27

7.86

ftA SJ7

100.00

6

40.76

5.92

CO CO

100. 00

a Preliminary report of the Natural Resources Survey of Rhode Island: Rhode Island Bur. Industrial 

Statistics Bull. 1 (Ann. Rept. 1909, pt. 3), p. 115, 1910. 

6 Furnished by G. L. Gross.

1. By Prof. Sharpies, of Boston. °

2. By State Assayer Perkins, of Rhode Island.

3. By same analyst as 2, from later sample.

4. Latest analysis, by English.

5 and 6. By Chase Palmer, of the U. S. Geological Survey, from samples obtained by E. S. Bastin and 

Gi W. Brown.

This material can hardly be considered a fuel and in fact is prepared and sold for foundry facings. Though the analyses given 

are supposed to be from a continuation of the same bed or carbonaceous zone as that which is being mined at Cranston for coal, the 

material at the Fenners Ledge appears to have been much more 

squeezed than that at the Budlong mine, which doubtless accounts 

for its more graphitic character as well as its higher percentage 

of ash. At this point, as shown in figure 1 (p. 19) and Plate IV 

(p. 18), the bed is as irregular as most metalliferous ore bodies. 

At the G. L. Gross mine, to the south, the bed appears to be more 

regular, and mining has been extended about 200 feet underground.

REASON FOB LOW HEAT VALUE OF RHODE ISLAND COAL.

Attention has already been called to the high ash and high moisture 

content of Rhode Island coal. In sample 9328, as given in the 

table on page 26, the ash and moisture together amount to 33.27 

per cent of the coal, practically one-third of it. In sample 9329 

they amount to 33.14 per cent; in sample 3330 to 54.45 per cent, 

or more than one-half, and so on. In contrast with these figures, 

the Pocahontas coal shown in analysis 5456 (p. 31) has only 6.49 

97887° Bull. 615 15 3
34 EHODE ISLAND COAL.

per cent of ash and moisture together, and the New River coal 

(analysis 5467, p. 31) has only 5.31 per cent. Since the ash and 

moisture are almost if not entirely inert matter, it is evident that if 

the coal is made up of two-thirds coal and one-third ash and moisture, 

it can have only two-thirds the heating value it would have if all coal.

But there is still another factor involved. If comparison is made 

between Rhode -Island coal and other coals on the ash-free and 

moisture-free basis, it is evident that there is still a marked difference. 

For example, none of the Rhode Island coals on this basis reach a 

heat yield of 14,000 British thermal units, whereas, of the competing 

coals listed none go under 14,800 and the best average 16,000 British 

thermal units. In other words, there is a difference of 1,000 to 2,000 

British thermal units in the heat value of the coaly matter or pure 

coal. The cause of this is fairly apparent from a further study of 

the analyses. It was noted above that if the moisture and ash are 

left out of consideration, Rhode Island coal has almost exactly the 

same composition as Pennsylvania anthracite; that is, about 95 per 

cent of fixed carbon and 5 °per cent of volatile matter. Why, then, 

do they not have the same relative heating power ?

If a study is made of the analysis of Pocahontas coal shown in the 

table on page 31, sample 5456, it maybe noted that, on the ash and 

moisture free basis the fixed carbon is 81.44 per cent and the total 

carbon 89.88 per cent. Therefore, 8.44 per cent of the carbon occurs 

in combination with the other elements of the coal. When Pocahontas coal is heated to 500° C., about two-thirds of the gas that is 

given off (water and tar having been separated out) is composed of 

carbon and hydrogen compounds about one-sixth is hydrogen and 

the other one-sixth is carbon dioxide, carbon monoxide, and illuminants. If the temperature is raised to 1,000° C., the gas is twothirds hydrogen, one-fourth carbon and hydrogen compounds, and 

the rest carbon dioxide, carbon monoxide, and illuminants.1 The 

hydrogen, carbon and hydrogen compounds, carbon monoxide, and 

illuminants are combustible. The carbon dioxide is not. In the 

specific tests to which reference has been made the carbon dioxide, 

ammonia,, and water of constitution which, added together, make up 

the "inert volatile matter," come to only 0.7 per cent.

Now, 1 pound of carbon in burning to carbon dioxide will yield 

about 14,400 British thermal units. If 81.44 per cent of the coal is 

fixed carbon, the fixed carbon in a pound of Pocahontas coal like 

sample 5456 should yield 11,727 British thermal units. But the coaly 

matter or "pure coal" of that sample is credited with 15,860 British 

thermal units. Evidently the remainder must come from the 

burning of the volatile matter. As we have seen, the volatile matter 

consists almost entirely of carbon and hydrogen in combustible form.

i Bur. Mines Bull. 1, p. 30,1910.
CHARACTER OF THE COAL. 35

So much of the hydrogen. a°s will come off in combination with oxygen 

in the form of water that is, an amount equal to one-eighth of the 

oxygen is deducted. As the oxygen amounts to 3.45 per cent, 

one-eighth of that or 0.43 per cent may be subtracted from 4.75 per 

cent of hydrogen, leaving 4.32 per cent of "available" hydrogen, 

as it is called*. Now, 0.0844 of a pound of carbon, the amount of 

carbon in the volatile matter of a pound of coal under consideration, 

will yield 14,400 X 0.0844 or 1,215 British thermal units. But 

1 pound of hydrogen when burned to water yields 62,048 British 

thermal units and 0.0432 of a pound of hydrogen, the amount in a 

pound of this coal, would therefore yield 2,680 British thermal units. 

The 2,680 and the 1,215 British thermal units added to the 11,727- 

British thermal units from the fixed carbon give 15,622 British 

thermal units, as compared with 15,860 obtained in the calorimeter 

test. As a matter of fact, certain elements affecting the result have 

not been taken into consideration in the above computation.

Similarly the analyses of anthracite coal from Lackawanna and 

Schuylkill counties, Pa. (analyses 1245 and 5953 to 5956, p. 30), 

show that apparently, though not probably, all the carbon is in the 

form of fixed carbon, and an analysis of the volatile matter may 

fail to show any hydrocarbons; but from the percentage of hydrogen 

and oxygen it is evident that there is still a considerable amount 

of " available" hydrogen left. For example, in the ash-free and 

moisture-free sample of anthracite culm from Lackawanna County 

(analysis 1245 (condition 3), p. 30), there are 3.17 per cent of hydrogen 

and 2.72 per cent of oxygen. As one-eighth of 2.72 per cent or 0.34 

per cent of hydrogen will satisfy the oxygen, 2.38 per cent of hydrogen 

is left for .burning. But 0.0238 of a pound, the amount of available 

hydrogen in a pound of that coal, will yield 1,376 British thermal 

units, so that the coal shows a heat value at least that much higher 

than that obtained from the fixed carbon alone.

In Rhode Island coal, as shown in the analyses (pp. 26-28), not only 

is all the carbon apparently in the form of fixed carbon but all the 

hydrogen is required to satisfy the oxygen, leaving none "available" 

for burning. In other words, on the face of it, the volatile matter 

of Rhode Island coal does not appear to contain any combustible 

matter. In fact, in most of the samples there is not enough hydrogen 

to satisfy the oxygen, so that some of the oxygen may be united 

with some of the carbon in the form of carbon dioxide. As the 

fixed carbon is determined by subtracting from 100 the ash, moisture, 

and volatile matter, and is therefore liable to include more than 

the carbon (for in some of these analyses it exceeds in amount the 

total carbon in the coal), it is probable that the volatile matter 

consists mainly of water and carbon dioxide and possibly some carbon 

monoxide.
36 RHODE ISLAND COAL.

If all the fixed carbon in Rhode Island0 coal were burned it would 

yield a higher calorific value for the coal than is actually obtained, 

which indicates that the volatile matter of that coal adds nothing 

to its heat value, and that the "fixed carbon" contains a small 

amount of noncombustible matter or loses some heat in the evaporation of the contained water.

In brief, though the small amount of volatile matter in Pocahontas 

coal is calculated to yield about one-fourth the heat value and the 

volatile matter in Pennsylvania anthracite is calculated to yield 

about one-tenth the heat value, the volatile matter in the Rhode 

Island coal appears to add little or nothing to the heat value, which

IUU

90

-P 

8 80

(D 

D_

0 70 

_Q

to

O

T) 

<D 60 

X

50 

4-0

9 530*

x.= 

o =

N 

la

9336

/

As received 

Air dried 

Ash and moisture free

jmbers are those of 

Moratory samples

y/

93

/

/ xg

30rv

S*

335

7 

7!

/*

336

9331

77<

)337~

35

,9,

77

/^

8

932£ 

3fK.

7^2f 

V

3337

7771

^932

^

'72

8

/

9331

/

I3 2 9

>£

^P

^9

-9328

933i

9335 

771 

337

6,000 7,000 8,000 9,000 10,000 11,000 12,000 13,000 14,00°

Heat value in British thermal units

FIGURE 3. Chart showing relation of carbon in Rhode Island coal to fuel value.

seems to be derived entirely from the fixed carbon. As a matter 

of fact, the calorific value of Rhode Island coal can be readily computed within probably 1 per cent by multiplying the percentage of 

fixed carbon by 144. Thus, if the percentage in one one-hundredth 

of a pound be multiplied by 14,400, it will be found to be generally 

a little higher than the actual figure obtained in the calorimeter. 

Thus in sample 9328 (p. 26) the fixed carbon is 64.43, and 0.6443 X 

14,400 gives 9,278 British thermal units, as compared with 9,230 

obtained in the calorimeter. In sample 9330 (p. 26) the fixed 

carbon in a pound, 0.4254, multiplied by 14,400 gives 6,025 British 

thermal units, as compared with 5,976 obtained in the test. In 

sample 9331 (p. 26) the fixed carbon should yield, by the above 

method of computation, 8,405 British thermal units, whereas the 

test gave 8,528; here the actual value is slightly above the value
CHARACTER OF THE COAL. 37

as computed. Figure 3 shows the relation between the fixed carbon 

and the British thermal unit value as determined. The chart shows 

first that the fixed carbon of the coal, whether from Portsmouthor Cranston, has an almost uniform heat value and that the heat 

value is expressed as stated above by a little below 144 British 

thermal units for each per cent of fixed carbon in the coal. The 

line expressing the average ratio as drawn has the ratio 1:143.

BEHAVIOR OF RHODE ISLAND COAL TOWARD MOISTURE.

The presence of such a high percentage of moisture in so hard a 

coal has always excited a peculiar interest. In this connection it 

was pointed out by Emmons in 1884 that the Portsmouth coal, at 

least, possessed the striking peculiarity of quickly taking up a large 

percentage of water under a moist condition of the atmosphere 

and as readily parting with it under a drier condition of the atmosphere. Emmons describes the following interesting experiments 

conducted by Gooch: 1

A sample of Portsmouth coal, * * * powdered and exposed for 24 hours in 

the balance room during the prevalence of a northwest wind, contained after exposure 

water amounting to 0.65 per cent of its weight when dried at 115°.

Water

.' (per cent).

The dried (at 115° C.) coal took up during 24 hours' exposure in the 

balance room, while the same wind was blowing, of its own 

weight. ...................................................... 0.15

After 16 hours' exposure over water it had taken up............. 8.46

After 24 hours'exposure over water it had taken up.............. 9.72

After 61 hours' exposure over water it had taken up.............. 12. 64

Alter 85 hours' exposure over water it had taken up.............. 12. 67

The percentage of water fell:

After 24 hours' exposure over H2S04 to.......................... 1.38

After 48 hours' exposure over H2S04 to.......................... .54

After 138 hours' exposure over H2S04 to......................... .64

A similar sample was wet thoroughly, dried with filter paper, and exposed 24 

hours in the balance room during a northwest wind. Its content of water in terms of 

coal dried at 115° C. amounted to 0.75 per cent.

Water 

(percent).

A sample of the drill core from Portsmouth (see analyses 5, 6, and 

7, p. 28), moistened thoroughly, dried with paper, and exposed 

24 hours during a northwest wind, contained, in terms of material dried at 115° C......................................... 0.81

The dried coal took up during 24 hours' exposure in balance room.. . 22 

It took up over water, in 16 hours............................. 8.96

It took up over water, in 24 hours............................. 10.32

It took up over water, in 61 hours............................. 12. 88

It took up over water, in 85 hours. .........."................. 13. 80

1 Emmons, A. B., Notes on the Rhode Island and Massachusetts coals: Am. Inst. Mln. Eng. Trans., 

vol. 13, pp. 512-513, 1885.
38 RHODE ISLAND COAL.

The coal contained of water, expressed in terms of itself dried at 115° C.:

Water 

(per cent).

After 24 hours' exposure over H2S04 ............................ 0.85

After 48 hours' exposure over H2S04 ............................ .53

After 138 hours' exposure over H2S04 . . ......................... .46

A sample of the same piece, exposed in the balance room without wetting, contained 

of water 0.72 per cent of the weight of the coal dried at 115° C.

A sample of the same piece, exposed in the balance room without wetting or drying 

in the air bath, contained of water, expressed in terms of itself dried at 115° C.:

"Water 

(percent).

After 16 hours' exposure over water............................. 11.45

After 21 hours' exposure over water....................^ ........ 13.26

After 37 hours' exposure over water............................. 16. 77

After 61 hours' exposure over water............................. 16. 91

After 85 hours' exposure over water............................. 16.87

After 109 hours' exposure over water............................ 16.85

The content of water expressed in percentage of coal dried at 115° C.:

After 24 hours' exposure over H2S04 , fell to..................... 1.84

After 48 hours' exposure over H2S04 , fell to..................... .83

After 138 hours' exposure over H2S04 , fell to..'.................. .71

For the sake of comparison, a piece of Pennsylvania anthracite was taken from the 

cellar and similarly treated. 

As it came from the bin it contained of water 4.69 per cent of the weight of the coal

dried at 115° C.:

Water 

(per cent).

Powdered and dried at 115° C., it contained.. I................. 4.42

After 26 hours' exposure over water............................. 5. 91

After 75 hours' exposure over water............................. 6.34

After 144 hours' exposure over water............................ 5.10

A similar piece (i. e., not powdered), exposed over water without previous drying 

in air bath, contained, in terms of weight of coal dried at 115° C.:

Water 

(per cent.)

After 30 hours' exposure over water............................. 5. 38

After 80 hours' exposure over water............'................. 5. 67

After 150 hours' exposure over water............................ 5.69

After 23 days' exposure over water.............................. 5.38

A piece of Cumberland bituminous coal contained, as it came from 

the bin (the sample was powdered), in terms of the coal dried at 

115° C.....................'.........:...................... 1.38

After 26 hours' exposure over water............................. 1. 98

After 75 hours' exposure over water............................. 2. 06

After 144 hours' exposure over water............................ 1. 95

UTILIZATION OF.RHODE ISLAND COAL.

KINDS OF USE.

Rhode Island anthracite may be employed for household use, 

steam production, metallurgic work, briquetting, brick burning, and 

similar work, the manufacture of water gas or producer gas for use 

directly or for power production to be transmitted electrically to
UTILIZATION OF THE COAL. 39

centers of distribution. The graphitic portions of the beds may be 

used for foundry facings and furnace linings.

Its suitability for building chimneys and other uses had been 

suggested at an early date, as indicated in Bryant's poem "A meditation on Rhode Island coal." Its successful household use at that 

time (before 1832) is indicated by the beginning of the poem:

I sat beside the glowing grate, fresh heaped with Newport coal.

That the difficulties of its burning had been fully appreciated are 

also indicated toward the end of the poem, where he says:

Thou shalt be coals of fire to those that hate thee, 

And warm the shins of all that underrate thee; 

Yea, they did wrong thee foully they who mocked 

Thy honest face, and said thou wouldst not burn; 

Of hewing thee to chimney pieces talked, 

And grew profane, and swore, in bitter scorn, 

That men might to thy inner caves retire, 

And there, unsinged, abide the.day of fire.

HOUSEHOLD USE.

Rhode Island coal has always been used in a small way for household heating and some householders are said to have used it for 40 

years or more. Samuel Sanford, who was well acquainted with the 

Portsmouth mines in the seventies, says that Portsmouth coal was 

then selling at the mine at $3.50 a ton and that a small amount was 

purchased and hauled away for household use, but that 90 per cent 

of the people living in the neighborhood preferred to burn Pennsylvania anthracite, costing at that time from $5.50 to $7.50 a ton. This 

condition has apparently prevailed during the whole history of the 

field.

In burning the coal is said to ignite very slowly and to snap violently and explode, tending to throw pieces of the coal out of the fire, 

but when once well ignited it burns very much like anthracite and 

gives ah intense heat. The ash is said to have almost the same bulk 

as the coal and as a rule to fuse and clinker badly. The intense heat 

is said to be destructive to stoves and utensils and the clinkering 

tends to destroy the grate bars. Probably as a result of this rapid 

burning it is said to burn itself out quickly and to require much more 

attention in firing and in keeping overnight than other coals.

It is said that by breaking the coal down fine and carefully screening it to remove dust it ignites more easily, as it will after thoroughly 

drying, which also prevents the snapping of the coal when first 

heated.

The existence of films of graphite in the coal along planes of slipping has been thought to be partly the cause of the slow ignition of 

the more graphitic coal. The breaking up of this coal aids in its 

ignition, it is supposed, by allowing freer passage of the heat.
40 RHODE ISLAND COAL.

In general, as compared with other anthracites and bituminous 

coals, as shown both by the tests in the laboratory and under the 

furnace, Rhode Island coal has only from 70 to 80 per cent of the heating power of other anthracites and from 60 to 70 per cent of the heating power of bituminous coals shipped into New England. Indeed, 

the poorer samples of Rhode Island coal show only about 40 per cent 

of the heating efficiency of competing coals. This fact, together with 

its slower ignition, its destructively hot fire, and the fact that it 

yields a maximum of eight times as much ash as competing coals and 

requires more frequent attention, fully explains its unsuccessful use 

for household heating in the past. It is the misfortune of Rhode 

Island coal that it must compete with the best coals of the United 

States, which are brought into its market by boat at very low rates.

At least two attempts have been made to briquet Rhode Island 

coal commercially, both of them by the Zwoyer process. Apparently neither attempt proved successful. Whether the process or the 

binder had anything to do with the lack of success is not known. It 

is claimed that the briquets first made, in 1898, fell to pieces, owing 

to the binder burning out before the coal became ignited, and the 

briquets made recently are said to have yielded dense volumes of 

smoke and soot that soon clogged the flues and chimneys. It may 

be doubted whether any of the binders in common use to-day will 

prove satisfactory in the household stove, in which the temperature 

is relatively low as compared with that of the furnaces under steam 

boilers for power. Experiments have since been made at Portsmouth, and the results of tests by the Bureau of Mines indicate that 

it will be possible to make briquets that will be practically smokeless 

and that will stand handling. It appears possible that experiments 

will develop a process of making briquets, probably with some admixture of a high gas coal, that wiU. give at least fairly successful results 

in household use.

The experiments published by the Bureau of Mines were made at 

St. Louis in 1906 by what was then the technologic branch of the 

United States Geological Survey. No test was made of Rhode 

Island coal alone, but two tests were made of that coal mixed with 

two different bituminous coals from Pennsylvania in the form of 

briquets. The manufacture and character of the briquets is described 

under the heading "Briquetting tests" (pp. 46-48). The tests were 

made on a sectional steam boiler, such as is in common use for house 

heating. The detailed results of these tests are given in Bulletin 27 of 

the Bureau of Mines. The economic results only are repeated here. 

For the sake of comparison there are also given the results obtained 

by similar tests made in the engineering laboratory of the University 

of Illinois, at Urbana, 111., on anthracite, coke, and Pocahontas coal.
UTILIZATION OF THE COAL. 41

Results of tests of briquetted fuels in house-heating boilers at St. Louis, Mo., and

Urbana, III.

Test number.

St.L.47...........

St.L.35...........

Urb.163...........

Urb. 185... ........

Urb. 173.... .......

Designation of fuel.

Pennsylvania No. 15 (one-half) and 

Rhode Island No. 1 (one-half). 

Pennsylvania No. 18 (one-half) and 

Rhode Island No. 1 (one-half).

Pocahontas ..............................

Economic results (pounds).

Equivalent evaporation from and 

at 212° F. per 

pound of fuel.

As fired.

C.55 

7.13

7.22 

7.98 

8.24

Dry.

6.94 

7.34

7.88 

8.37 

8.98

Fuel per hour per 

100 square feet of 

radiating surface 

(mean load carried during test).

As fired.

4.57 

4.19

4.15 

3.75 

3.65

Dry.

4.57 

4.14

3.99 

3.61 

3.58

Test 

number.

St. L. 47....

St.L.35....

Urb.163....

Urb. 185....

Urb. 173....

Designation of fuel.

Pennsylvania No. 15 (one-half) and

Rhode Island No. 1 (one-half).

Pennsylvania No. 18 (one-half) and 

Rhode Island No. 1 (one-half).

Efficiency (per cent).

Boiler and 

furnace 

(dry-fuel 

basis).

52.01

52.24

57.58

62.50

57. CO

Plant 

(fuel as 

fired 

basis).

49.44

51.43

54.91

61.44

53.92

Fuel at $1 per 2,000 

pounds.

Cost in

cents per 

100 square 

feet of 

radiating 

surface 

per hour 

(mean load 

carried

during

test).

0.2290

.2100

.208

.188

.183

Cost (in 

cents) of 

evaporating 

1,000 

pounds of 

water from 

and at

tit a .

7.64

7.01

6.92

6.27

6.07

As far as the experiments were conducted it was 

shown that the pitch binders used are not suitable for the furnace working at the low 

temperatures common in the household boiler, as they volatilize and in most cases 

escape unburned or were deposited on the surface of the boiler. This coating generally 

burned off once or twice a day, causing a high temperature in the flue and, as a consequence, danger of fire. :

A test of "treated Rhode Island coal" by the Bureau of Mines, 

though not conclusive, failed, it is said, to show improvement in the 

burning or heating qualities of the coal.

USE IN STEAM RAISING.

The same qualities of the coal that are shown by household use 

are evident in its use in steam raising. (See description of action on 

grate in test 401, p. 45.) In this use its heat-giving value is of prime 

importance. The tests of the calorimeter show Rhode Island coal to

Snodgrass, J. M., Fuel tests of house-heating boilers: Univ. Illinois Bull. 31,1909.
42 RHODE ISLAND COAL.

have from 40 to 80 per cent of the heating value of competing coals. 

A number of careful commercial tests liave been made, for one of 

which the general results are available.

In 1874 a test of the Cranston coal was made at the pumping 

station of the Providence Waterworks. Unfortunately a table giving 

the detailed figures for the run has been lost, but the report" which 

accompanied the table is still available. The following extracts 

from the report, a copy of which was furnished by the city engineer's office, give the most complete and satisfactory demonstration 

of the steaming qualities of the coal that has been found. The 

report in part is as follows:

CRANSTON COAL.

The Cranston coal used at Pettaconset is a lusterless anthracite, containing graphite, 

quartz, and traces of asb'estoa and sulphur among its impurities. It yields about 26 

per cent of ash. Its specific gravity is 2.30 and weight 64.75 pounds (? 133.75 pounds) 

to the cubic foot. Its evaporation power is about 7.76 pounds of water from and at 

212° per pound of coal, which is the same as 6.6 pounds of water from 60° to steam at 

60 pounds.

The Lackawanna coal is a brilliant anthracite, containing about 18 per cent of ash. 

Its specific gravity is 1.60 and weighs 52.82 pounds (? 99.8 pounds) to the cubic foot. 

Its evaporative power is about 10.74 pounds of water from and at 212° per pound of 

coal, which is the same as 9.10 pounds of water from 60° to steam at 60 pounds.

The evaporative power of the Cranston coal is therefore about 72 per cent of the 

Lackawanna.

The following explanation of the lost table is given:

Line 7. Rate of delivery is based upon the number of strokes during the run or 

experiment, length of stroke as observed, and a deduction of 2£ per cent from the 

theoretical discharge of the pump. This percentage of loss is established by repeated 

weir measurements during former experiments, f * *

Line 22. The rate of combustion is based on the coal used during the experiment.

Line 23. In making up the total amount of fuel used during the day a small amount 

of coke was charged as Lackawanna coal, and the wood as equal to one-half its weight 

of coal.

Lines 24 and 25 are placed in juxtaposition to show the large amount of coal used 

in banking.

Line 26. The percentage of ash is made up from the total fuel used during the day. 

It was dampened and weighed wet and so given in the table. The Lackawanna ash 

was found to weigh 78 per cent of the recorded weight when dry. The Cranston ash 

95£ per cent..

Lines 27 and 28. The water evaporated per pound of coal or combustible is based 

on the fuel recorded during the run or experiment, and is probably too large by so 

much as the coal charged to the run is too little. ^

The figures previously given as the evaporative power, viz, 7.76 and 10.74, are a 

mean of the quantity evaporated during the run and during the day per pound of 

combustible. The water was measured with a meter, said meter being tested before 

and after the experiment and proper correction made.

Line 29 is added as a check upon the quantity of water used during the different 

days. It will be observed that it was nearly uniform.

Line 30. The length of stroke is a mean of quarter-hourly observations.
UTILIZATION OF THE COAL. 43

Line 31. The duty is based upon the theoretical discharge of the pump and the 

static head. While this does not give the engine full credit for its work for this 

trial, it was considered the least.liable to error. It may be added, however, that other 

experiments have shown the friction head for pump, main, and check valves to be 

about 3.9 per cent of static head. * *.*

Line 35 is given to show the relative duty based upon the coal used during the 

day or week, which is probably the truest criterion of the value of the coal. Line 

32, on column K, is taken as unity as a fair standard of comparison.

It will be observed that columns M and N show the value of the Cranston coal 

about 72 per cent of the Lackawanna.

Line 36 makes the basis of comparison with the water evaporated daily, but a 

mean was obtained as previously explained, viz, 72 per cent, which seems to agree 

with the duty, as it should.

About 10 per cent of Lackawanna coal and a small portion of coke was used with 

the Cranston coal, to aid the fire when burning irregularly on the grate. Less of 

this was used as experience was gained in its use. It is probable that with care and 

skill no other coal need %e used in connection with it. A large loss was due to the 

small coal, partially burned, falling through the grate; although an occasional effort 

was made to sift it and reuse it, no practical gain was made.

It was thought that a slower rate of combustion would be favorable to the coal, 

and permission was given to the agent for the coal to burn it slower. January 28th 

and 29th, it will be observed, it was reduced a little, and a slight increase of duty 

obtained; but it seems that this diminished rate of combustion as recorded is probably in part due to screenings of small coal deducted from the coal charged and also 

deducted from the ash, thus reducing the ash very much for those two days, but 

increasing it proportionately the next day. However, a slight increase of duty is seen 

for the 10-days' run, where the rate of combustion is 10.16 pounds of coal per square 

foot of grate per hour over the first week's run, where it was 10.56 pounds.

As it was the effort of the agent to keep the engine up to the usual speed, and with 

very good result, it was necessary to increase the rate of combustion over the usual 

rate, viz, 7.30 pounds, in order to effect it. It seems very probable that a slower 

rate than was used would be advantageous.

Steaming tests of Rhode Island coal from Cranston have been 

made by the United States Geological Survey and the Bureau of 

Mines on the coal alone and briquet ted with other high volatile coals. 

Results of these tests are as follows:

RHODE ISLAND NO. I.1

Anthracite graphitic coal from Cranston, Providence County (near Providence), 

was designated Rhode Island No. 1. This sample was mined from surface workings 

at Cranston and commercially would be classed as run-of-mine coal. It was shipped 

under the inspection of J. S. Burrows and was used in making steaming test 401; 

also mixed with Utah No. 1 in steam tests (on briquets) 414 and 415, coking tests 

141 and 157, and briquetting test 127; mixed with Utah No. 2 in steaming test 416 

(on briquets) and briquetting test 133; mixed with Pennsylvania No. 15 in briquetting test 184; and mixed with Pennsylvania No. 18 in briquetting test 243.

1 Holmes, J. A., in charge, Report of the United States fuel-testing plant at St. Louis, Mo.: U. S. 

Geol. Survey Bull. 332, pp. 223-224,1908.
44 SSODE ISLAND COAL. 

Chemical analyses of Rhode Island No. 1.

Air-drying loss. .....................................

Proximate: 

Moisture. .... ..................................

Volatile matter. . ................................

Fixed carbon. ...................................

Ash.............................................

Ultimate:

Carbon ........................................

Nitrogen. .......................................

Oxygen. . .......................................

Ash.............................................

Sulphur. ........................................

Calorific value (as received): 

Determined 

Calories. ....................................

Calculated from ultimate analysis 

Calories. ....................................

British thermal units. .......................

Car sample.o

3216 

2.00

2.41 

4.92 

73.61 

19.06 

.07

.90 

75.10 

.17 

4.70

6,109

10,996 

6,176

11,117

Steaming tests. 6

401

2.33 

2.47

78.72 

16.48 

.08

.67 

79.49 

.18 

2.71 

16.87 

.08

0

414

2.45 

24.21 

62.60 

10.74 

.41

2.95 

78.63 

.74 

6.25 

11.01 

.42

415

2.27 

22.20 

65.29 

10.24 

.41

3.13

77.64 

.74 

7.59 

10.48 

.42

416

5.85 

25.20 

59.56 

9.39 

.85

2.94 

76.42 

.73 

9.04 

9.97 

.90

a Sample from producer-gas test 113 (failure) treated as car sample.

6 Proximate analysis of fuel as fired; ultimate analysis of dry fuel figured from car sample.

Steaming tests of Rhode Island No. 1 (briquets).

Duration of test. ....................................

Force of draft:

dry fuel...

3h water.. 

....do.... OF

Dry fuel usedper square foot of grate surface, per hour, .pounds. . 

Equivalent water evaporated per square foot of water-heating 

surface per hour. ................................. . .pounds. .

Water apparently evaporated per pound of fuel as fired 

Water evaporated from and at 212° F.: 

Per pound of fuel as fired........................ 

Per pound of dry fuel...................... ......

Fuel as fired: 

Per indicated horsepower hour. ..................

Dry fuel: 

Per indicated horsepower hour ...................

.pounds..

.pounds. . 

....do....

....do....

percent..

.pounds. . 

....do....

....do.... 

....do....

Test 401.

8.05 

11,639

0.54 

.18

20.22

1.99 

55.8 

4.19

4.81 

4.93 

7.70 

40.91

5.88 

7.26

5.74 

7.08

Test 414.

5.0 

12,845

0.67 

.21

18.42

2.96 

83.0 

6.75

7.86 

8.05 

9.35 

60.52

3.60 

4.44

3.51 

4.34

Test 415.

5.0 

12,823

0.62 

.06 

2,119 

19.01

3.25 

91.0 

7.17

8.36 

8.55 

9.75 

64.39

3.38 

4.18

3.31 

4.08

Test 416.

10.02 

12,244

0.58 

.20 

2,053 

21.51

2.78 

78.0 

4.26

4.95 

5.26 

7.70 

41.49

5.71 

7.05

5.38 

6.64

a Too low to be read with Wanner optical pyrometer. Forced draft used on this test.

Remarks: Tests 414 and 415 on briquets made from Rhode Island No. 1 and Utah 

No. 1 mixed. The briquets burned freely, with short, yellow flame; did not crack 

open, but coked throughout and held together well. No smoke; burned very much 

like anthracite, except for color of flame. These comparative tests on Rhode Island 

coal No. 1 gave only 55.8 per cent capacity and were unsatisfactory. (See test 401 

above.) Heavy clinker, which was tough and plastic when hot and brittle when 

cold, but did not stick to the grate.

Test 416 on briquets from test 133, made from Rhode Island No. 1 and Utah No. 

2 mixed. With natural draft the briquets burned with a very short flame; with 

forced draft they burned with a longer flame, giving a hotter fire. Briquets did not 

coke or hold together well in the fire. No smoke; see briquetting test 127 for comparative data. No clinker; a large amount of ash resulted, due to the crumbling 

of the briquets and the falling of the loose particles through the grate.
UTILIZATION OF THE COAL. 45

In Bulletin 23 of the Bureau of Mines the following additional 

data are given on page 179 for test 401 and on page 191 for tests 

414 to 416:

Test No. 401 (No. 1). The coal burned slowly, with a short, bluish flame. It 

became hot and fused together, cutting off the air supply through the grate. Hooking 

the fire helped slightly. Small pieces of coal burned more completely than large 

ones. About three-fourths inch coal would be the best size for steaming purposes. 

Large pieces burn only on the surface, because the ash fuses and adheres to the coal, 

thus insulating the inner portion. Low capacity was developed, owing to the fact 

that high enough draft could not be obtained with the fan blower. In order to develop 

the rated capacity, a draft of 3 to 4 inches of water would be necessary. A rocking 

grate would be preferable to a flat grate. Pressure was used in. the ash pit. Automatic air admission was not operated. The furnace temperature was too low to be 

read by the Wanner optical pyrometer.

Test No. 414 (briquets). One-quarter of the observations of furnace temperature 

were too low to be read by the Wanner optical pyrometer. The average is not representative of the test. The briquets did not crumble in the fire and burned with a 

short flame. Automatic air admission was not operated. A heavy layer of plastic 

clinker formed on the grate. It was broken with some difficulty.

Test No. 415 (briquets). The briquets did not crumble in the fire and burned with 

a short flame. Automatic air admission was not operated. A heavy layer of plastic 

clinker formed on the grate. It was broken with some difficulty. Forced draft was 

used.

Test No. 416 (briquets). The briquets crumbled in the fire, did not cake, and 

burned with a long flame. Automatic air admission was not operated. A large 

amount of free ash formed on the grate. It was easily removed. Forced draft was 

used.

For the sake of comparison there are given below figures from 

the tests by the Bureau of Mines at St. Louis, Mo., and at Norfolk, 

Va., showing, first, the horsepower developed and^second, the pounds 

of water evaporated per pound of fuel of Rhode Island coal on the 

one hand and of some of the competing coals on the other.

Results of steaming tests by the Bureau of Mines on Rhode Island coal and other coals that 

are shipped into New England.

Bureau of Mines 

designation.

490 Md. No. 2..............

237 Pa. No. 8..............

36 Pa. No. 3...............

401 R. I. No. 1.............

46 W. Va. No. 12...........

56W.Va. No. 11. .........

39W.Va.No.6. ..........

296 W. Va. No. 21 .........

414 Utah No. 1 and R. I.

No. 1.

415 Utah No. 1 and R. I.

No. 1.

416 Utah No. 2 and R. I.

No. 1.

Coal.

Georges Creek. ....

Anthracite culm . .

.....do............

Pocahontas No. 8. .

Mixed ............

.....do............

.....do............

Location.

Frostburg. ....

Scrant^n......

Cranston......

Big Sandy....

Winifrede.....

Kind of 

sample.

Run of mine . .

.....do.........

Culm. ........

Run of mine. .

.....do........

.....do........

.....do........

.....do........

.....do........

Horsepower 

developed

on test.

239.2

174.2

184.5

117.1

206.1

213.7

213.2

213.8

174.3

191.2

163.7

Pounds of

water

evaporated

per pound 

offuel

equivalent

from and

at 212° F.

9.87

9.85

8.01

4.81

9.74

9.54

9.88

9.69

7.86

8.36

4.95
46 ° RHODE ISLAND COAL.

A:

According to these figures, Rhode Island coal alone yields from 54 

to 68 per cent as much horsepower as the other coals listed and from 

48 to 60 per cent as many pounds of water evaporated per pound of 

fuel. Lest it be thought that the highest figures have been selected 

for the competing coals, it may be mentioned that in other tests 

Pocahontas coal developed horsepower as high as 268 and New River 

coal as high as 367. As 20 tons of coal was used and every effort was 

made that the coal should be representative of that being regularly 

mined, the results may be accepted as accurate. As the car sample 

analysis of this coal (p. 44) shows it to have been above rather than 

below the average, it may be safely stated that, judged by analyses, 

calorimeter tests, and tests in actual practice, Rhode Island coal in 

making steam will yield from 40 to 80 per cent as many heat units as 

the coals with which it must compete to-day.

T7SE IN METALLURGY.

Rhode Island coal has been used successfully in the reduction of 

copper ore and in the metallurgy of iron, as already stated under the 

heading " History of development." At the time of its successful 

use anthracite coal was used in the blast furnace and the furnaces 

were much smaller than at present. To-day coke has been substituted for anthracite and is being used exclusively. The furnaces 

have been enlarged both in size and output. No figures are at hand 

which would form the basis for a comparison of the availability of 

Rhode Island anthracite as compared with coke in the modern fur- "" 

nace, but a general consideration of the reasons for the use of coke 

in the modern furnace and its cost would suggest that Rhode Island 

coal could not compete with coke either in cost or availability. It 

is quite possible that for foundry use and in small reheating furnaces, 

under certain conditions, it might be still possible to use Rhode Island 

coal in spite of the cost.

BRIQTJETTING TESTS.

In addition to the actual commercial tests of Rhode Island coal 

when made into briquets, the Bureau of Mines has made a number 

of briquetting tests with that coal.1 The analyses of the coal used, 

both alone and mixed, will be given first, as none of the tests 

were made on the Rhode Island coal alone. Rhode Island No. 1 

was from Cranston; Pennsylvania No. 15 was B or Miller coal from 

Wehrum, Indiana County; Pennsylvania No. 18 was the same coal 

from Lloydell, Cambria County; Utah No. 1 was from Huntington 

Creek, Carbon County; Utah No. 2 was from Coalville, Summit 

County.

1 Holmes, J. A., op. cit., pp. 201 et seq.
UTILIZATION OF THE COAL. 

Analyses of coals used in briquetting tests.

Proximate:

Ash.....................

Ultimate:

Ash......................

SuMmr.................

Calorific value (as received): 

DeterminedBritish thermal units

Calculated from ultimate 

analyses 

R.I. 

No. 1, 

car 

sample.

991 A

2.00

2.41

4.92

73. Cl

19.00 

.07

90

75.10

.17

4.70

6,109

10,996

6.176

11,117

Pa. 

No. 15, 

car 

sample.

4082

9 sn

3.13

17.61

09. 45

9.81 

3.77

4.62

76.41

1.14

4 OK

7.664

13,795

Pa.

No. 18, 

car 

sample.

4509

4.10

4.46

15.44

71.63

8.47 

1.49

4.80

77.43

11.28

6.53

7,601

13,682

Utah 

No. 1, 

car 

sample.

3199

3.80

6.05

42.02

47.06

4.87 

.55

5.76

72.32

1 38

15.12

7,300

13,151

7, 189

12,940

Utah 

No. 2, 

car 

sample.

3259

2.30

12.66

38.30

43.19

5.85 

1.39

Half 

R.I. 

No. 1, 

half 

Pa. 

No. 15.

.4913

0.74

15.96

69.71

13.59 

2.61

3.05

77.48

.49

2.C5

13.70

2.C3

Half 

R.I. 

No. 1, 

half 

Pa. 

No. 18.

1.34

16.39

70.34

11.93 

1.37

3.46

77.79

.53

4.74

12.09

1.39

Half 

oR. I. 

No. 1, 

half 

Utah 

No. 1.

2.45

24.21

62.60

10.74 

.41

2.95

78.63

.74

6.25

11.01

.42

Half 

R.I. 

No. 1. 

half 

Utah 

No. 2.

5.85

25.20

59.56

9.39

.85

76.42

.73

9.04

9.97

.90

The briquets are thus described. (See also pp. 43-44.)

Test 184. Pennsylvania No. 15 was mixed with an equal portion of Rhode Island 

No. 1 (run of mine) in this test. Excellent briquets were made with 6.25 per cent 

binder on the Renfrew machine. Although the pitch used had a low melting point, 

the briquets handled well from the machine, and piled without sticking. The outer 

surface waa very hard and smooth, and broke without crumbling, giving a smooth 

fracture and sharp edges.

Test 243. Equal parts of Pennsylvania No. 18 and Rhode Island No. 1, both run 

of mine. An effort was made to improve the burning qualities by increasing the 

melting point of the binder, but owing to the hardness of the pitch used and insufficient pressure, these briquets were not satisfactory. They could not be handled when 

warm without many being broken, but when cold were brittle, producing considerable 

slack in handling. No physical tests were made.

Test 127 (Utah No. 1 with Rhode Island coal No. 1). This test was made to prove 

the value of briquetting a good fuel with one that is commercially worthless. A highvolatile coal, low in ash, was chosen to mix with the graphitic coal. Various percentages were tried, but 47 per cent of each coal and 6 per cent binder made an entirely 

satisfactory briquet. Six per cent binder made excellent briquets; outer surface 

smooth and polished and very hard; briquets broke without crumbling, and broken 

surfaces were smooth and hard.

. Test 133 (Utah No. 1 and Rhode Island No. 1). In this test Rhode Island No. 1, 

the only available high-volatile (carbon?) coal, was chosen in order to supplement the 

data of test 127. Test 133 was not successful, as coal showed characteristics of lignite, 

both in briquetting and burning. The mixture contained 47 per cent of each coal. 

Briquets with 6 per cent binder were tough and hard; outer surface smooth and very 

hard; the fracture rough but clean and firm. No drop tests were made.
48 RHODE ISLAND COAL.

The tests of the briquets gave the following results: 

Results of tests of briquets.

Size as used: 

Over one-fourth inch. ....................

Details of manufacture:

BinderKind.................................

Weight of 

Fuel briquetted. .....................

Heat value per pound 

Drop test (1-inch screen): 

Held. ....................................

Tumbler test (1-inch screen): 

. Held.....................................

Weathering test:

....... .per cent. .

...........do....

...........do....

...........do....

.............°F..

........pounds.. 

...........do....

...........do....

Test 184.

0.8 

7.0

15.0

22.2

55.0

Renf.

185

w. g. p.

6.25

10.000 

0.5

/ o!3, 712

\clO,996 

12, 703

16,969

68.5

31.5

- 93. 0

7.0

91.4

11

A

Test 243.

1.0

6.8

17.6

25.2

49.4

Renf.

185

w. g. p.

4625

8.0

2,000

613,682

c 10, 996 

13,387

16,576

Test 127.

1.0

5.8

9.4

Ofi A

57.4

Renf.

149

3410

6

16,000 

n 5

12,259

10 COO

16,478

214

B

Test 133.

1.2

6.0

19.2

Of; fi

48.0

Renf.

149

w. g. p.

3410

6

37,000 

n v>

11,032 

11,527

16,478

190

Pennsylvania No. 15. 6 Pennsylvania No. 18. Rhode Island No. 1.

In these descriptions Renf. refers to the Renfrew machine; w. g. p. 

is water-gas pitch; the drop test consisted in dropping 50 pounds 

of the briquets in a box a distance of 6| feet onto an iron plate, 

screening each time what would go through a 17-mesh wire screen. 

In the tumbler test 50 pounds were revolved in the Opermayer tum- 

.bler 56 times and then screened through 1-inch and -j^-inch mesh 

screens. Under "Weathering test," A means unchanged; B, shape 

unchanged, surface pitted or dulled or edges worn; C, outside 

briquets weathered, fracture not sharp.

House-heating tests were made for briquets described in tests 184 

and 243 and steaming testsjrom briquets made in tests 127 and 133. 

These have been described under the headings "House heating" and 

"Steam raising."

BRICK BURNING AND SIMILAR WORK.

The use of this coal for brick burning or the burning of limestone 

for fertilizers has been suggested. In this work the broken or fine 

coal is placed between layers of brick in a kiln or between layers of 

limestone when burned in piles in thev>fields. The writer does not 

know of such use having been made oJ3 the coal and is not prepared 

to predict how successful it would be. The ash apparently would
UTILIZATION OP THE COAL. 49

not be a serious detriment in such use. The coal might also be used 

for the roasting of ores and in other work where the ash is not a serious 

detriment and high heat rather than long-continued heat is desired.

INDIRECT USE AS WATER GAS OR PRODUCER GAS.

There has been a widespread feeling for many years that Rhode 

Island coal would some day come to its own through its use in the 

production of water gas or producer gas for metallurgic work, or 

more especially for use in the gas engine in the, production of electric 

power to be used for manufacturing near the mines or to be transmitted to the cities. Its possible use in the manufacture of water 

gas was mentioned by Shaler in 1899, who says "that a test of a few 

tons of the coal had been made in the manufacture of water gas and 

that it was well suited to the purpose." 1 It has been thought 

that a few plants situated at the mines, by being specially designed 

and specially manned, would be able to deal with the peculiar characteristics of the coal satisfactorily and thus take advantage of its 

location in saving transportation costs.

In principle producer gas is made by forcing air through a mass 

of incandescent coal so controlled that the oxygen of the air finds 

a surplus of carbon and unites to form carbon monoxide which is 

combustible and passed off with the nitrogen, which is inert, the 

product being known as producer gas. In the manufacture of water 

gas superheated steam is used in place of the air, and the product 

consists of hydrogen with carbon monoxide instead of the inert 

nitrogen. Water gas, therefore, yields about twice as many heat 

units as the same quantity of producer gas or, if enriched, from four 

to five times as many. Modern practice has tended toward the producer-gas plant as the most efficient method of transforming the 

power of the coal immediately into electric power, though with Rhode 

Island coal water gas may prove the better of the two.

A number of tests have been made by the Bureau of Mines on 

Rhode Island coal in the producer-gas plant. Though it may be 

conceded that future tests may, and doubtless will, lead to changes 

in the construction of the producer-gas plant that will more fully 

adapt it to the peculiar behavior of Rhode Island coal and that with 

such an improved and specially devised plant better results would be 

obtained, yet the figures here quoted may be accepted as fairly indicative of the results obtainable with present forms of the producer.

The results of the producer-gas tests are described in Bulletin 13 

of the Bureau of Mines, and because of the interest in this phase of 

the problem the results of the tests are given in full.

i Shaler, N. S., Woodworth, J. B., Foer: ->., A. F., Geology of the Narragansett Basin; U. S. Geol. 

Survey Mon. 33, p. 84,1899.

97887° Bull 615 15 i
50 RHODE ISLAND COAL. *^

The coal used in test 113 was mined from the Budlong pit, at '

Cranston, under the supervision of J. S. Burrows. ** i

The coal for tests 190 and 191 was later shipped from the same .^

pit by Budlong & Son. It consisted principally of small lumps, ' r . ;

1 or 2 inches in size, and a few larger lumps were broken up by the >

hammer before firing and the fine material was screened out. Before , making this test a little of it was tried in the blacksmith forge with ~

the following result, as described in a preliminary report: 1 "* ~

Before the testing was started a small quantity of this fuel was burned in a black- .;v~ 

smith's forge in order to note any special characteristics that it might exhibit while \7 

burning, and thus aid in the operation of the producer during the test. On the tblacksmith's forge it was very slow to ignite, but when well ignited it burnt very much 

like anthracite and gave an intense heat. When first fired, it snapped violently and ; * 

frequently small lumps of coal were thrown forcibly from the fire. After burning for 

about half an hour in the forge there was a considerable amount of slag or clinker %?'"" 

about the consistency of thick tar. Upon examination this slag did not appear to _ 

consist entirely of fused ash, but to contain quite a portion of the unburnt fuel in the 

fused state. Although the conditions in the blacksmith forge of heavy forced draft ^ 

were unlike the conditions that would exist in the producer, it was expected that the ) 

tendency of the fuel to fuse would prevent to some extent its more successful use in -^ , 

the producer.

The coal for test 194, amounting to about 20 tons, was obtained

from the Portsmouth mine under the supervision of C. A. Fisher, of V/!

the United States Geological Survey. It was taken in the heading ,

at the 800-foot level, about 1,200 feet south of the slope. At this |

point the coal was being mined and mining had extended about 50 *- i

feet beyond the face of the heading, which had been left when the -;

mine was previously abandoned. The coal at this point, as described *"><

by Mr. Brown 2 v r

is some 65 inches thick, showing in the upper and lower portions of the coal bed some ^.^

2 or 3 inches of graphitic ahaly material, which probably results from shear. The coal 

shows a considerable degree of purity, excepting near the middle of the bed where c, 

1$ or 2 inches of "bone" with quartz and later pyrite occur. The bedding is rather 

thin, probably one-half inch, but in some cases there is a thick bed of some 8 inches ^ 

of massive coal. Throughout the bed, increasing toward the edges of the roll, there occur 

numerous offset veins of quartz, sometimes reaching a thickness of 2 or 3 inches, but "*?'' ' 

penetrating, in a large number of cases, in mere shreds and veinlets of silica. * * * ^ 

No run-of-mine coal could be taken and the tests therefore are made upon the best ^""~ 

coal that the mine can produce. ^

The tests are described as follows: 3 J

*i Rhode Island No. 1, test 113. Rhode Island No. 1 was a graphitic coal having a '

gray, metallic appearance. Some of the lumps were extremely hard, but others were *»*>

soft. This material was charged on top of a good fuel bed of Tennessee coal capable /i

of making a gas of average quality. As the charging continued, the heat value of the v^

1 Preliminary report of the natural resources survey of Rhode Island: Rhode Island Bur. Industrial ^i 

Statistics Bull. 1 (Ann. Kept. 1909, pt. 3), p. 105,1910.

2 Idem, pp. 95-96. ^ 

a Bur. Mines Bull. 13, pp. 199, 342-346, 349,1911. '

> v

/ 
UTILIZATION' OF THE COAL. 51

gas steadily decreased, whereas the temperature of the fuel bed increased. After 

15 hours the calorimeter would not work because of the low-heat value of the gas, 

which, at that time, was about 55 British thermal units per cubic foot. Three hours 

later the engine stopped and subsequent attempts to start it again were unsuccessful.

* V. *****

Pittsburgh No. 19A, test 190. The fuel used during this test was a Ehode Island 

graphitic anthracite. It was heavy and hard and a freshly broken surface presented 

a glossy appearance; it contained a large percentage of graphite and one could mark 

with pieces of the coal as readily as with a pencil.

Because this fuel ignited slowly the coke bed was allowed to become thoroughly 

incandescent before any of the graphitic coal was charged, and while the fuel bed 

was being built up a maximum draft was maintained. About an hour after the first 

charge of coal was made the gas burned steadily at the test cock, and although it was 

low in heat value the engine was started. After running about 30 minutes, however, 

on no load it stopped, due to the poor quality of the gas. After the engine was started 

the draft in the producer decreased considerably on account of the small amount of 

gas consumed by the engine. With this reduced draft the fire died down and the gaa 

decreased rapidly in heat value. Soon after the engine stopped the gas was discharged 

into the atmosphere, and with a good draft the fire soon began to improve; the gas, 

however, was of unsatisfactory quality for some time. The engine was finally started 

again, and in order to maintain a sufficient draft to produce combustible gas a portion 

of the gas was allowed to escape through the purge pipe. During the remainder of 

the day (about 1£ hours) the producer gave no trouble and a little over half of full load 

was maintained at the engine. At the close of the day's run the producer was seemingly in good condition for the night's shutdown. The fire, however, did not keep 

and the next morning it was necessary to rekindle it with wood. As is shown by 

the graphic log, the results obtained were more satisfactory after the first day's 

trial. From one to two hours each morning were required to get the producer in 

condition to generate gas of sufficient heat value to start the engine, and at the close 

of each day's run the fire was banked with a good grade of coal in order to hold it overnight. Throughout the greater part of the test also a considerable portion of the gas 

was necessarily allowed to escape to the atmosphere in order to maintain the required 

draft. The quantity of gas thus wasted was difficult to estimate, and for this reason 

little value can be attached to the figures given in the table on page 357 [p. 53 of this 

paper] for fuel consumed per horsepower hour, since no allowance for this waste was 

made.

Throughout the test the fuel bed increased rapidly in thickness, and at the end of 

the fourth day the producer was completely filled with fuel and refuse. One of the 

characteristics of this graphitic coal is that its ash occupies nearly the same volume 

as the original fuel. The resistance of the fuel bed was not excessive at any time and 

few shots were made. Throughout the run little trouble was experienced from clinker, 

* although a considerable quantity formed and3 adhered firmly to the producer walls.

Pittsburgh No. 19A, test 191. A second test was made on Pittsburgh No. 19A in an 

attempt to reduce the waste of gas and thus obtain results that would be of more value 

than those obtained from test 190. Instead of kindling a fire on the coke bed, as in the 

preceding tests, 1,000 pounds of the graphitic coal, making a layer 1 foot thick, were 

first charged on top of the coke in the producer, and then the fire was started on top of 

this. The result of this change of procedure was satisfactory; gas of sufficient heat 

value to run the engine was generated in about an hour and a quarter from the time 

of starting the fire, and at the end of the test practically all of the coke was recovered. 

During the first three hours of the test no gas was discharged into the atmosphere, and 

consequently there was no waste; but at the end of this period the fire began to die 

out and the gas diminished in heat value. It was evident that the draft in the
52 RHODE ISLAND COAL.

producer was too low; consequently a portion of the gas was allowed to escape, and 

soon afterwards the fuel bed was in much better condition and the heat value of the 

gas was considerably higher.

Throughout the test it was frequently necessary to resort to this method of increasing 

the draft in order to generate gas of sufficient heat value to run the engine. Nevertheless the quantity of gas thus wasted was much less than in the preceding test, 

and from the results given in the table it may be seen that the fuel consumption 

was also much less. On the other hand, the effort to operate with a minimum waste of 

gas resulted in a much lower average draft than in the preceding test, and the effect 

of this was to lower the heat value of the gas, and consequently to diminish the 

average load which could be carried at the engine.

The thickness of the fuel bed increased rapidly, as in the preceding test, but during 

the last part of the run there was much more clinker formed than at any time during

test 190.

* * * * * * *

Pittsburgh No. 62, test 194- Pittsburgh No. 62 was a graphitic anthracite from 

Rhode Island, having the same characteristics as Pittsburgh No. 19A. It behaved in 

a similar manner in the producer, being slow to ignite and requiring a good draft to 

generate a gas of fair quality. As in previous tests with this fuel, a part of the gas was 

wasted during much of the time, and for this reason little value can be attached to 

the figures for fuel consumption per brake horsepower-hour given in the table on 

page 357 [p. 53 of this paper]. This graphitic coal would not hold fire overnight in 

the producer, and in order to avoid rekindling each morning the fire was banked at 

the end of each day's run with a good grade of bituminous coal, which held the fire 

satisfactorily. The coal thus used was reduced to its equivalent weight of graphitic 

coal and charged against the test. From 1 £ to 2 hours each morning, after starting the 

producer, was required before a gas capable of running the engine was generated. 

Throughout the test the gas was rather variable in quality and the load carried was 

somewhat irregular, as is shown by the graphic log. A comparatively small amount of 

clinker formed during this run.

Results of producer-gas tests made at Pittsburgh, Pa.

' -

Proximate analysis of fuel (per cent):

Ash..................................................................

Fuel charged in producer (pounds) : a ° 

TotalDry ..............................................................

Per hour 

Dry..............................................................

Per square foot of fuel-bed area per hour 

Dry.....................;........................................

Refuse:

Combustible in refuse 

Per cent. . ........................................................

No. 19A, 

Auburn. 

R.I.

22.33

3.70

2.11

71.45

22.74

.06

11,335

10,916

8,339

507.6

488.8

373.4

39.2

37.7

28.8

3,000

1,648

55.0

No. 19A, 

Auburn, 

R.I.

29.00

4.80

2.50

69.90

22.80

.10

9,454

9,000

6,844

326.0

310.3

236.0

25.2

24.0

18.2

2,138

845

39.5

No. 62, 

Portsmouth, 

R.I.

32.17

11.50

3.41

63.59

21. 50

.59

11,334

10,031

7,594

352.3

311.8

236.1

27.2

24.1

18.2

2,815

551

55.1

Figures given include the fuel equivalent of coke consumed during test.
UTILIZATION OP THE COAL. 53

Results of producer-gas tests made at Pittsburgh, Pa. Continued.

No. 19A,

Auburn.

B.I.

No. 19A,

Auburn.

R.I.

Combustible consumed:

Total........................................................pounds.. 6,691 5,999

Percent.............................................................. 80.2 87.7

Coke in fixing bed (pounds):

Total chargedin producer............................................ 813 1,017

Eecovered from refuse................................................ 166 989

Consumed during test................................................ 647 28

Calorific value (British thermal units): 

Fuel per pound 

As fired........................................................... 10,121 10,090

Dry.............................................................. 10,510 10,590

Combustible...................................................... 13,759 13,930

Standard gas 

Prom 1 pound of fuel 

As fired....................................................... 2,587 3,996

Dry.......................................................... 2,696 4,205

Per cubic foot..................................................... 99.1 94.7

Consumed per horsepower hour 

Indicated..................................................... 9,296 10,076

Brake........................................................ 11,258 12,548

Electrical........................................;............ 13,319 15,010

Equivalent to stated horsepower per minute 

Gas............................................................... 21,919 21,737

Indicated......................................................... 5,993 5,489

Brake............................................................ 4,950 4,407

Electrical......................................................... 4,187 3,682

Standard gas produced (cubic feet) 

Total................................................................. 296,348 399,379

Perhour........:..................................................... 13,271 13,772

Per pound of fuel charged 

Asfired........................................................... 26.1 42.2

Dry.............................................................. 27.2 44.4

Combustible...................................................... 35.5 58.4

Standard gas consumed by engine (cubic feet):

Perhour.............................................................. 13,261 13,762

Per horsepower hour 

Indicated......................................................... 93.8 106.4

Brake............................................................ 113.6 132.5

Electrical......................................................... 134.4 158.5

Composition of gas (per cent of volume):

CO*................................................................... 6.98 7.24

Os..................................................................... .13 .06

C2H4 .................................................................. .00 .00

CO................................................................... 23.25 22.74

H2 .................................................................... 6.33 5.28

CH4 .................................................................. .38 .34

Nj.................................................................... 62.93 64.34

Water used:

Vaporizer (pounds) 

Total............................................................. 1,015 1,054

Per hour.......................................................... 45.5 36.3

Per pound of fuel fired............................................ .09 .11

Wet scrubber (cubic feet) 

Total............................................................. 6,296 4.503

Perhour.......................................................... 282 155

Per 1,000 cubic feet'standard gas.................................. 21.3 11.3

Engine jackets (cubic feet) 

Total.............................................................. 2,557 3,382

Perhour.......................................................... 115 121

Per brake-horsepower hour....................................... .98 1.16

Entire plant (cubic leet) 

Total............................................................. 8,869 7,902

Perhour.......................................................... 397 273

Per brake-horsepower hour....................................... 3.40 2.62

Average barometric pressure (inches of mercury)....................:..... 29.18 29.12

Average pressure (inches of water):

Gas leaving producer................................................. 6.21 6.99

Gas leaving economizer............................................... 6.57 7.24

Gas leaving wet scrubber............................................. 10.68 10.04

Gas entering dry scrubber............................................ + 5.55 + 6.04

Gas entering meter................................................... +2.97 +2.93

Gas leaving meter.................................................... + .62 + .39

Average temperatures (°F.):

Air entermgeconomizer............................................... 110 103

Air and vapor entering producer...................................... 391 363

Gas leaving producer................................................... 1,214 1,048

Gas leaving economizer............................................... 616 543

^ Vaporizer used only in part of test.
54 RHODE ISLAND COAL.

Results of producer-gas tests made at Pittsburgh, Pa. Continued.

No. 19A,

Auburn.

K.I.

No. 19A,

Auburn.

R.I.

No. 62, Portsmouth. 

R.I.

Average temperatures (°F.) Continued. « Gas leaving wet scrubber.............................................

Gas entering meter...................................................

Jacket water:

Entering..........................................................

Leaving..........................................................

Gas Jiorsepower...........................................................

Revolutions per minute of gas engine.....................................

Explosions per minute per cylinder.......................................

Indicated horsepower, total...............................................

Brake horsepower:

Developed at engine..................................................

Commercially available...............................................

Electrical horsepower:

Developed at switchboard............................................

Commercially available...............................................

Average electrical horsepower required to run auxiliary machinery........

Economic results: Fuel charged in producer per horsepower hour (pounds): 

Per indicated horsepower developed 

As fired..........................................................

Dry...............................:.............................

Combustible......................................................

Per brake horsepower 

Developed at engine 

As fired......................................................

Dry.........................................................

Combustible..................................................

Commercially available 

As fired......................................................

Dry.........................................................

Combustible..................................................

Per electrical horsepowerDeveloped at switchboard 

As fired.......................................................

Dry.........................................................

Combustible..................................................

Commercially available 

As fired.......................................................

Dry.........................................................

Combustible..................................................

Efficiency (per cent):

Of conversion and cleaning gas. .*.................. '. ...................

Of producer plant.....................................................

Thermal, based on stated horsepower and gas horsepower 

Indicated........................................................

Brake...........................................................

Electrical........................................................

Of entire plant, based on fuel charged per stated horsepower per hourBrake horsepower developed at engine............................

Brake horsepower commercially available.........................

Electrical horsepower developed at switchboard.................

Electrical horsepower commercially available.....................

81

85

72

137

516.8

261.2

130.6

141.3

116.7

113.4

98.7

95.9

2.8

3.59

3.46

2.64

4.35

4.19

3.20

4.48

4.31

3.29

5.14

4.95

3.78

5.29

5.10

3,89

 25.6 

25.5

27.3

22.6

19.1

5.8 

5.6 

4.9 

4.8

85

76

135

512.5

260.7

130.4

129.4

103.9

100.7

86.8

84.1

2.7

2.52

2.40

1.82

3.14

2.99

2.27

3.24

3.08

2.34

3.76

3.57

2.72

3.88

3.69

2.81

39.7

39.4

25.3

20.3

16.9

8.0 

7.8 

6.7 

6.5

47

43

39

119

522.5

268.8

134.4

147.8

123.5

120.1

105.2

102.3

2.9

2.38

2.11

1.60

2.85

2.52

1.91

2.93

2.60

1.97

3.35

2.96

2.24

3.44

3.05

2.31

36.2

36.0

28.3

23.6

20.1

8.6 

8.3 

7.3 

7.1

In order that comparison may be made with the results of tests of 

other coals there is given a supplementary table, 1 showing the pounds 

of fuel of Rhode Island and some other coals charged in the producer 

per commercial brake horsepower and electric horsepower, as that 

forms the best basis for comparison.

i Bur. Mines Bull. 13, p. 357,1911.
4 I

Economic results of Rhode Island coals as compared with certain other coals of the Un

Test 

No.

170 

171 

172 

173 

174 

175 

176 

177 

178 

179 

180 

183 

184 

185 

186 

187 

188 

189 

190 

191 

192 

193 

194

Designation 

of fuel.

Pittsburgh: 

No. 1.... 

No. 1A..

Slack.... 

No. 4.... 

Slack.... 

No. 5A.. 

No.SA..

No. 5A..

No.5A..

No. 7.... 

No. 8.... 

No. 12... 

No. 13... 

No. 14...

No. 12... 

No. 11... 

No. 14...

No. 18... 

No. 19A. 

No. 19A. 

No. 36... 

No. 35... 

No. 62...

Location of mine or deposit.

Madison. Pa. .................

Elizabeth City, N. C... .......

Pocahontas, Va. .. . ...........

.....do........................

.....do........................

.....do........................

Lytle, Tex.. ..................

Walston. Pa. .................

Lehigh,N. Dak..............

lone, Cal.....................

Scranton, N. Dak.............

Sherrard, HI. .................

Auburn, R. I. ................

.....do........................

Coalville, Utah...............

Tono, Wash.................. 

Portsmouth, R.I.............

Fuel charged in producer p

Per indicated horsepower developed.

As 

fired.

1.09 

1.40 

1.26 

2.78 

1.34 

1.02 

.98 

1.13 

1.04 

2.03 

2.13 

1.91 

2.60 

3.23 

2.30 

2.36 

2.19 

2.33 

3.59 

2.52 

1.68 

2.02 

2.38

Dry.

1.07 

1.37 

1.20 

2.39 

1.29 

1.00 

.97 

1.11 

1.02 

1.39 

1.47 

1.86 

1.69 

2.01 

2.25 

1.54 

1.97 

2.13 

3.46 

2.40 

1.48 

1.70 

2.11

Combustible.

0.96 

1.14 

1.05 

1.62 

1.14 

.83 

.86 

.94 

.87 

1.17 

1.19 

1.28 

1.51 

1.57 

1.52 

1.37 

1.58 

1.59 

2.64 

1.82 

1.40 

1.46 

1.60

Per brake horsepower

Developed at engine.

As 

fired.

1.26 

1.62 

1.47 

3.27 

1.63 

1.19 

1.15 

1.52 

1.33 

2.38 

2.50 

2.34 

3.10 

3.96 

2.76 

2.82 

2.64 

2.88 

4.35 

3.14 

1.96 

2.36 

2.85

Dry.

1.23 

1.58 

1.41 

2.81 

1.57 

1.17 

1.13 

1.49 

1.31 

1.62 

1.72 

2.28 

2.01 

2.47 

2.70 

1.84 

2.37 

2.63 

4.19 

2.99 

1.73 

1.99 

2.52

Combustible.

1.11 

1.32 

1.23 

1.90 

1.39 

.97 

1.00 

1.27 

1.11 

1.37 

1.39 

1.57 

1.80 

1.93 

1.82 

1.64 

1.89 

1.97 

3.20 

2.27 

1.63 

1.72 

1.91

Commerci

As 

fired.

1.28 

1.66 

1.51 

3.36 

1.66 

1.23 

1.18 

1.61 

1.39 

2.46 

2.59 

2.45 

3.17 

4.08 

2.86 

2.88 

2.73 

2.98 

4.48 

3.24 

2.02 

2.45 

2.93
56 RHODE ISLAND COAL. o -

"* 

In general, a study of the full tables as published in Bulletin 13 of 

the Bureau of Mines shows that it requires from 1 to 2 pounds of 

Pocahontas coal or bituminous coal from central Pennsylvania to f * 

produce 1 available electric horsepower-hour as compared with 

2.85 to 5.29 pounds of Rhode Island coal. This may be stated differ- ~* 

ently as follows: One ton of Pocahontas coal or central Pennsylvania ._ 

bituminous coal will yield 1,000 to 2,000 available horsepower-hours, 

whereas Rhode Island coal, according to the tests made, will yield 

from 375 to 700 horsepower-hours. Generally, the yield from Rhode . ^ 

Island coal appears to have been about one-third of that from the 

other coals named. If account be taken of the cost and interest for ""* 

transmission lines from the field to centers of distribution, as from >. 

Portsmouth to Providence, and the added cost of handling the larger 

quantity of coal necessary and the very much larger quantity of ash, 

it appears that Rhode Island coal at the mouth of the mine for use *-r 

in the producer-gas plant, is worth only one-fourth to one-third the 

value of competing coals delivered at Providence or Boston. If it v~ be assumed, however, that specially designed apparatus would prevent ,;_ 

the loss of gas noted in the experiments it seems possible that from 

2 to 3 pounds of Rhode Island coal could be made to produce 1 ^ 

electric horsepower-hour, averaging say 2£ pounds, against an aver- *- 

age of, say, 1£ pounds for competing steam coals. With the added 

costs referred to above, it seems that a ton of average selected Rhode 

Island coal should deliver in Providence or Boston electric power ^ 

equivalent to that obtained from one-half ton of average competing ' 

coals.

In November, 1913, Pocahontas coal was selling at wholesale in ^- 

Providence and Boston at a little under $4 a ton. In order to compete with power produced by that coal, Rhode Island coal of the *"" 

best grade must be mined and delivered at the mouth of the mine ^ 

to a producer-gas plant for not over half that price, or $2 a ton.

In using Rhode Island coal in the producer-gas plant, the cost ~" 

of mining might be reduced sufficiently to allow competition by put- ^. 

ting the producer-gas plant in the mine, as low in the basin as possible. As the coal carries no combustible volatile matter, neither ^ 

the coal nor the dust should offer any danger of fire or explosion and, 

as the rocks adjacent to the coal are very firm, the cost of preparing f 

rooms should be little more than the cost of excavation. Such ~*' 

rooms are now used for pumps in the Portsmouth mine. By plac- ^- 

ing the plant low the coal can be lowered by gravity from the higher 

levels. The plant could also be installed in small movable units, ** 

including a gas producer and gas engine, the power to be taken out ^ 

of the mine as electricity. By this method it might prove feasible 

to move the unit plants from one of these large lenses to another. 

As these lenses in the Portsmouth mine and at Cranston appear to
; . . CONCLUSIONS. 57

 -

1 have, in places, a length of 1,000 feet or more and a width of 100

i or 200 feet or more and, at Portsmouth, an average thickness of 4£

 ^ feet, it seems that one of them should yield sufficient tonnage to

 > cover the cost of moving and installation of a small unit. Whether ^^ . . .... such a mine installation, by eliminating the cost of the lift out of the

mine, would reduce the total cost sufficiently to render competition 

~V possible would have to be demonstrated.

^ USE FOB FOUNDRY FACINGS AND FURNACE LININGS.

.^ In the preceding sections the utilization of Rhode Island anthracite has been discussed. This has been the specific purpose of this 

:TX bulletin. A little may, however, be said in regard to the use of the 

\r*y more graphitic portions of the beds. Though all the anthracite contains more or less graphite, portions of the beds have been changed 

"** entirely to what appears to be graphite. Such a bed at Fenners 

^ Ledge is being mined at present in an open cut by Mr. Fenner and 

\ sold for foundry facings, for which it appears to be well adapted after 

the proper preparation. At the old Gross mine, to the south, an 

T attempt was made to prepare the graphite for market. Buildings 

were erected and machinery installed. The graphite was crushed 

'\, and screened, using expensive brass sieves. The process adopted did 

not prove successful, apparently owing to the difficulty of separating 

) the fine quartz.

'<* Graphite has also been mined at Bridgeton, Valley Falls, and

^ ; Tiverton, at the first and last places from open cuts, but at Valley

Falls the workings were extended underground." The material was

* used for foundry facings and some of it for furnace linings.

"^ CONCLUSIONS.

* A review of the physical and chemical character of Rhode Island 

,_ coal, the history of its past exploitation and use, and past and recent 

tests of its use leads to the following general conclusions: 

Rhode Island coal is a high-ash, high-moisture, graphitic anthra-

-^ cite coal of high specific gravity.

Calorimeter tests show it to yield from 6,000 to 11,000 British

" ; thermal units, averaging, as taken from the mine, about 9,000 British thermal units, or about 10,000 after air drying. As compared ' 

with coals shipped to New England, with which it must compete,

^ which range from 12,000 British thermal units for Pennsyl-

-^ vania anthracite culm to nearly 15,000 British thermal units, and 

average 13,000 for anthracite and about 14,500 for bituminous as

^ mined, Rhode Island coal yields on the average from 60 to 70 per 

cent of the heat value of these competing coals. The best of the 

Rhode Island coal may reach 90 per cent of the heat value of the

~'f poorest competing coal and 80 per cent of the better grade.
58 EHODE ISLAND COAL.

-»"'

A careful test in actual practice showed Rhode Island coal to have 

72 per cent of the efficiency of Lackawanna coal.

In experimental tests by the Bureau of Mines, Rhode Island coal f 

yielded from 54 to 68 per cent as much horsepower as the other coals i 

listed and from 48 to 60 per cent as many pounds of water evaporated "*' 

per pound of fuel. _,

In household and steam use it is found to ignite slowly and with / 

difficulty and to make so hot a fire as to destroy stove tops, melt \ 

vessels and boilers placed on it, and destroy furnace lining's, so that ^*-_ 

the fire is difficult to maintain and control. Its ignition and burning 

are improved by breaking down to small sizes and careful screening. "*"

Rhode Island coal has been successfully used in the metallurgy of -^ 

copper and iron. Evidence is lacking to show that it could compete 

with coke in the modern furnace. v

Rhode Island coal has been briquetted, but without commercial j^*.1 

success. It is believed that future tests may make possible the production of briquets that hold together and do not smoke. ^ f

The high specific gravity renders washing otf this coal with present / 

methods difficult if not impossible.

In producer-gas tests by the Bureau of Mines, Rhode Island coal "* 

yielded from 375 to 700 horsepower-hours per ton of coal, as compared ^ 

with 1,00.0 to 2,000 available horsepower-hours for competing coals. : 

Specially designed plants, it seems reasonable to suppose, might be ! 

made to yield at least one-half as much power with Rhode Island ! 

coal as with competing coals.

In general, it appears that at the present time the best outlook '( 

for Rhode Island coal is in the production of electric power at the ^ 

mines, either in steam engines or by means of specially devised 

producer-gas or water-gas plants. It appears further, however, that ^*^~~ 

this can not be done with financial success until it can be shown 

that Rhode Island coal can be mined and delivered at the furnace for less than one-half the wholesale price of competing coals in 

Providence and Boston. n ^

v ^

PAPERS AND REPORTS.

Papers and reports to which reference is made or which are of value 

in connection with this subject are listed below in chronologic order:

1. Providence Journal. Through the kindness of officials of the Providence Public "" 

Library, the writer had access to the old files of the Journal and to a large £-«- 

number of clippings on the subject of Khode Island coal. These have formed 

the basis of much of the section on the history of development (pp. 7-14). ^

2. Hearing on the memorial of the New England Coal Mining Co. before the select

special committee of the General Assembly of Rhode Island and Providence KPlantations, together with the report of the committee, 1838.

3. Report and bill to the Commonwealth of Massachusetts relating to the coal mines

of the State, 1839. w
PAPEES AND REPORTS. 59

4. Jackson, C. T., Report on the geologic and agricultural survey of the State of 

Rhode Island, Providence, 1840.

5. Hitchcock, E. T., Final report on the geology of Massachusetts, Northampton, 

1841.

6. Mount Hope Coal Co., The coal beds of Rhode Island, 1852.

7. Hitchcock, E. T., The coal field of Bristol County and of Rhode Island: Am. 

Jour. Sci., 2d ser., vol. 16, pp. 227-336, 1853.

8. Hitchcock, E. T., Geology of the Island of Aquidneck: Proc. Am. Assoc. Adv. Sci., 

vol. 14, pp. 112-137,1860.

9. Rhode Island Society for the Encouragement of Domestic Industry, Providence, 

1869.

10. Memorial of T. S. Ridgway, in relation to the coal field of Rhode Island, presented to the General Assembly, 1870.

11. Emmons, A. B., Notes on the Rhode Island and Massachusetts coals: Am. Inst. 

Min. Eng. Trans., vol. 13, pp. 510-517, 1885.

V 12. Adams, W. BL, Eng. and Min. Jour., 1886. (Referred to as having described 

some tests on Rhode Island coal; could not be located.)

"* 13. Providence Franklin Society. Report on the geology of Rhode Island, Providence, 1887. (Gives a complete list of papers on the geology of Rhode Island 

up to the time of publication.)

5 14. Shaler, N. S., Woodworth, J. B., Foerste, A. F., Geology of the Narragansett Basin:

U. S. Geol. Survey Mon. 33, 1899. (This is a complete comprehensive report

on the geology of the coal basin containing the Rhode Island coal. It does not

deal at great length with the coal from either the stratigraphic or the commercial

fe standpoint.)

15. Second Geol. Survey Pennsylvania Summary Rept., vol. 3, pt. 1, 1895.

16. Lord, N. W., Experimental work conducted in the chemical laboratory of the 

United States fuel-testing plant at St. Louis, Mo.: II. S. Geol. Survey Bull. 323, 

9 1907.

17. Breckenridge, L. P., A study of four hundred steaming tests, made at the fueltesting plant, St. Louis, Mo.: U. S. Geol. Survey Bull. 325, 1907.

^ 18. Holmes, J. A., in charge, Report of the United States fuel-testing plant at St. 

Louis, Mo.: U. S. Geol. Survey Bull. 332,1908.

^ 19. Burrows, J. S., Mine sampling and chemical analyses of coals tested at the United 

States fuel-testing plant, Norfolk, Va.: U. S. Geol. Survey Bull. 362, 1908.

§? 20. Randall, D. T., Tests of coal and briquets as fuel for house-heating boilers: U. S. 

Geol. Survey Bull. 366, 1908.

21. Snodgrass, J. M., Fuel tests of house-heating boilers: University of Illinois Bull. 

^ 31, 1909.

22. Preliminary report of the natural resources survey of Rhode Island: Rhode 

Island Bur. Industrial Statistics Bull. 1 (Ann. Rept. 1909, pt. 3), 1910.

23. Fernald, R. H., and Smith, C. D., Re'sume' of producer-gas investigations: Bur.

Mines Bull. 13, 1911. *) .

24. Lord, N. W., and others, Analyses of coal in the United States: Bur. Mines

Bull. 22,1913.

N Brief references were made in the Engineering and Mining Journal 

and other journals and papers given in the list published in item 13.
f\
INDEX.

A.

Page.

Analyses of coals used in briquets............ 47

of Rhode Island anthracite........... 20-29,44

Aquidneck Coal Co., operations of.......... 8,9,10

Ash, cause of high content of................ 19

determinations of........................ 21-22

percentage of............................ 23-33

B. 

Bibliography................................ 58-59

Blackstone Coal Co., operations of........... 11

Brick burning, possible use of the coal for.... 48-49

Briquets, attempts to make................. 13

tests of...................... 40-41,43-45,46-48

Bryant.W.C., cited......................... 39

Budlong mine, anthracite in, diagram showing thickness of.................. 19

face of bed north of mouth of slope, plato

showing.......................... 12

north end of, plate showing.............. 19

open cut in, plate showing............... 12

operation of...... J...................... 12

surface plant at, plate showing........... 13

Bureau of Mines, briquetting tests by........ 46-48

steaming tests of various coals by........ 45-46

tests of the coal in a producer-gas plant by 49-57

C.

Chemical character of the coal............ 17,23-33

Clay, test of, desirable....................... 16

Compressed Coal Co., operations of........... 13

Cranston coal, briquetting tests of..... 43-45,46-48

mining of................................ 14

producer-gas tests of..................... 50-57

steam test of............................. 42-43

Cranston Coal Co., operations of............. 12

Cumberland, coal found in................... 8

D. 

Drilling, results of........................... 17

Durfee, W. F., interest revived by........... 11-12

Electricity, use of coal for.................... 7

Eminons, A. B., cited....................... 37-38

Fenner Ledge, mining at.................... 14

graphite mine at, view in................ 16

Foundry facings, use of graphite for.......... 57

Furnace linings, use of graphite for.......... 57

G.

Gas producer, advantage of placing, in mine. 56-57 

Graphite, content of......................... 20

Fenner Ledge, analyses of............... 33

produced from coal by heat.............. 18-19

uses of................................... 57

Page. 

Heat value, low, reason for.................. 33-37

Heating power, chart showing............... 24

comparison of........................... 32

Household use of the coal.................... 39-41

L. °

Lackawannacoal, ashin..................... 29

comparison of, with Cranston coal....... 42-43

heating power of......................... 35

Lenses, irregular, formed by pressure........ 18

Limo burning, possible use of the coal for.... 48-49

Lotteries granted to aid in mining coal....... 7,8

M. 

Mansfield, Mass., analyses of coals from...... 29

coal mining at........................... 9

Mansfield Coal Co., operations of............ 9

Mansfield Mining Co., operations of.......... 9

Massachusetts Mining Co., operations of..... 9

Metallurgy, use of the coal in............. 10,11.46

Mining, cost of, conditions affecting.......... 14-17

Mitchell, Thomas, operations of............. 12

Moisture, behavior of coal toward......... 32,37-38

percentage of............................ 23-33

Mount Hope Mining Co., operations of....... 10

N.

New England Coal Mining Co., operations of. 8-9 

New York Carbon Iron Co., operations of.... 11

Newport County coals, analyses of........... 26

Nichols, Purton, mines opened by........... 7

P. 

Pennsylvania, analyses of coals from......... 30

Physical character of the coal................ 20-21

Pocahontas coal, heating power of........... 34-35

Pocasset Coal Co., operations of.............. 10

Porter, J. B.,and Durley, R. J.,cited....... 22

Portsmouth coal, analyses of................ 28,29

behavior of, toward moisture............ 37-38

producer-gas test of.................... '.. 50-57

Portsmouth Coal Co. of 1847, operations of... 9 

Portsmouth Coal Co. of 1912, North and South

mines of, equipment of.......... 14

operations of............................ 14

South mine of, plate showing surface plant

at............................... 13

Pressure, effects of, on the coal...... 6,14-15,17-19

regional differences of.................... 19

Producer gas, tests of the coal for............ 49-57

Providence County coalsj analyses of........ 27

Providence Waterworks, test of coal at...... 10-11

Pyrite, content of........................... 20,21

Quartz, content of........................... 20,21

Quartz veins, formation of................... 19

61
62 INDEX.

R.

Page.

Revolutionary War, use of coal during....... 7

Rhode Island coal, character of.......... 5-6,57-58

compared with other coals when used in

a producer-gas plant............. 55-56

history of............................. 7-9,9-14

proper and improper modes of using.... 6-7,10

Rhode Island Coal Co. of 1809, operations of. 8 

Rhode Island Coal Co. of 1840, operations of. 9 

Rhode Island Coal Co. of 1909, operations of. 13-14 

Rhode Island coal field, sketch map of....... 6

Roger Williams mine, working of............ 11

S. 

Snodgrass, J. M., cited....................... 41

Specific gravity, determinations of........... 21-22

Standish, Miles, operations of..............:. 12

Steam raising, use of the coal in............. 41-46

T.

Taunton Copper Co., operations of. 

use of coal by..................

Page.

10

. 5,10

U. 

Uses, practicable, of Rhode Island coal...... 38-39

V. 

Virginia, analyses of coals from.............. 31

W.

Water gas, possible use of the coal for. 

West 'Virginia, analyses of coals from. 

Worcester Steel Works, operations of.

o