DEPARTMENT OF THE INTERIOR 

WATER-SUPPLY 

AND 

IRRIGATION PAPERS 

OF THE 

UNITED STATES GEOLOGICAL SURVEY 

No. 41 

THE WINDMILL: ITS EFFICIENCY AND 

ECONOMIC USE, l' ART I.-MURPHY 

WASHINGTON 

GOVERNMEN1' PRINTING OFFICE 

1901 
1RRIGATION REPORTS. 

The following list contains titles and brief descriptions of the principal reports 

relating to water supply and irrigation prepared by the United States Geological 

Survey ~inca 1890 : 1890. 

First Annual Report of the United States Irrigation Survey, 1890; octavo, 123 pp. 

Printed as Part II, Irrigation, of the Tenth Annual Report of the United States Geological Survey, 1888-89. Contains a statement of the origin of the Irrigation Survey, a preliminary 

report on the organization and prosecution of the survey of the arid lauds for purposes of 

irrigation, and report of work done during 1890. 

1891. 

Second Annual Report of the United States Irrigation Survey, 1891; octavo, 395 pp. 

Published as Part II, Irrigation, of the Eleventh Annual Report of the United States 

Geological Survey, 1880-00. Con tams a description of the hydrography of the nrid region and of the engineering operations carried on by the Irrigation Survey during 1890; also the statement of the Director of the Survey to the House Committee on Irrigation, and other 

papers, including a bibliography of irrigation literature. Illustrated by 29 plates and 4 

figures. 

Third Annual Report of the United States Irrigation Survey, 1891; octavo, 576 pp. 

Printed as Part II of the Twelfth Annual Report of the United States Geolo~Pcal Survey, 1890-91. Contains "Report upon tbe location and survey of reservoir sites durmg the fiscal 

year ended June 30, 1801," by A. H. Thomvson; "Hydrography of the arid regions," by F. H. Newell; "Irrigation In India," by Herbert M. Wilson. Illustrated by 93 plates and 

190 figures. 

Bulletins of the Eleventh Census of the United States upon irrigation, prepared by 

F. H. Newell; quarto. 

No. 35, Irrigation in Arizona; No. 60, Irrigation in New Mexico; No. 85, 

Irrigation in Utah; No. 107, Irrigation in Wyoming; No. 153, Irrigation in 

Montana; No. 157, Irrigation in Idaho; No. 163, Irrigation in Nevada; No. 178, 

Irrigation in Oregon; No. 193, Artesian wells for irrigation; No. 198, Irrigation in Washington. 1892. 

Irrigation of western United States, by F. H. Newell; extra census bulletin No. 23, 

September 9, 1892; quarto, 22 pp. 

Contains tabulations showing the total number, average size, ete., of irrigated holdings, the total area and average size of irrigated farms in the subhumid regions, the percentage of number of farms irrigated, character of crops, value of irrigated lands, the average cost of Irrigation, the investment and profits, together with a resume of the water supply and a description of irrigation by artesian wells. Illustrated by colored maps, showing the 

location and relative extent of the irrigated areas. 

1893. 

Thirteenth Annual Report of the United States Geological Survey, 1891-!l2, Part 

III, Irrigation, 1893; octavo, 486 pp. 

Consists of three papers: "Water supply for irrigation," by F. H. Newell; "American 

engineering" and "Engineering results of the Irrigation Survey," by Herbert M. Wilson; 

and "Construction of topographic maps and selection and survey of reservoir ites," by A. H. Thompson. illustrated by 77 plates and 119 figures. 

A geological reconnaissance in central Washington, by Israel Cook Russell, 18!l3; 

octavo, 108 pp., 15 nlates. Bulletin No. 108 of the United States Geological 

Survey; price, 15 cents. 

Contains a description of the examination of the geologic structure In and adjacent to the drainage basin of Yakima River and the great plains of the Columbia to the east of this area, with special reference to the occurrence of artesian waters. 

1894. 

Report on agriculture by irrigation in the western part of the United States at the 

Eleventh Census, 1890, by F. H. Newell, 1894; quarto, 283 pp. 

Consists of a general description of the condition of irrigation in the United States, the area irrigated, cost of works, their value and profits; also describes the water supply, the 

value of water, of artesian welL~, reservoirs, !'Tid other details; then takes up each State 

and Territory in order, giving a general description of the condition of agriculture by inigation, and dis<'usses the physical conditions and local peculiarities in each county. 

Fourteenth Annual Report of the United States Geological Survey, 1892-!)3, in two 

parts; Part II, Accompanying papers, 1894; octavo, 597 pp. 

Contains papers on "Potable waters of the eastern United States," by W J McGee; 

"Natural mineral waters of the United States," by A. C. Peale; and "Results of stream measurements," by F. H- Newell. Illustrated by maps and diagrams. 

IRR 41 (Continued on third page of cover-) 
DEPARTMENT OF THE INTERIOR 

WATER-SUPPLY 

AND 

IRRIGATION PAPERS 

OF THE 

UNITED STATES GEOLOGICAL SURVEY 

No. 41 

WASHINGTON 

GOVERNMEN'l' PRINTING OFFICE 

1901 

UNITED STATES GEOLOGICAL SURVEY 

CHARLES D. WALCO'r'f, DfRECTOR 

THE WINDMILL: 

ITS EFFICIENCY AND ECONOMIC USE 

PART I 

BY EDWARD CHARLES MURPHY 

WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1901 

CONTENTS. 

Page. 

Letter of transmittal _ .. _ .. ___ . __ . _________ . _ ... _ .. _ . ____________________ . 9 

Introduction ___ . _____ . ___ . ______ . _________ . _______ . _______ .. _ _ _ _ _ _ _ _ _ _ __ _ 11 

Classification of windmills .. ________ . ____________ .. ____________________ . _ _ 12 

Regulating devices . _____ . __________ .. ___ . ____ . __ . _ .. ______ . _. ____ . ___ . __ . _ 14 

Ear 1 y experiments ____ . _ . _______________ . ___ .... _ _ _ _ _ _ _ _ _ _ . __ . __ . ___ . _ . _ _ _ 15 

Experiments by writer .. _________ . ___ . __ . __ . _________ . __ ... ____ . _ _ _ _ _ _ _ _ _ _ 21 

Scope of tests .. ____ -_____ . ____ . . _ _ _ _ __ .. _ .... _ _ _ _ _ _ _ . ______ . ___ . ____ . _ 22 

Pumping mills _ .. _____ ... ___ . _____ . _. _________ . _ . ___ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 22 

Wells near Garden, Kansas ____ . ______ :.. __________ . ____ . _. _ _ _ _ _ _ _ _ _ _ 22 

Pumps _ _ _ _ _ _ __ . _ _ . ________ . ______ . _____ . _ . _ .. _ ... __ . __ .. _. __ . _ 23 

Instruments and methods.--------------------------------------· 24 

Mills tested . _____ . __ .. ___ . . _ . _ . _____ : ___ . _____ . __ ... __ . ____ . ___ . 27 

Discussion of results of tests . __ .. _ . . _______ . _ . _. ______ . _ _ _ _ _ _ _ _. 63 

Relation between wind velocity and strokes of pump __ . _ .. _. _ _ _ 65 

Useful work . _ . _ . . ___ . . . . . _ .. _. _. ___ . ____ . ___ . ___________ .. _ _ 65 

Pressure-tank system .. _ . _ _ . __________ .. _____ . __ ... ___ •.. ______ .. 68 

Comparison of three pumping Aermotora _ . ______ . __ . _ .. __ . _ _ _ 69 

Useful work of two pumping mills in a given time __ ._.________ 69 

Proper load. _____ . ____ . ____ . _____ .. ______ .. __ .. __ . _____ . _ _ _ _ _ _ 71 

Index, note concerning _ .. __ . _ ... ___ ... _____ ... ____ ..... __ . _________________ . _ 72 

5 

ILLUSTRATIONS. 

PLATE I. Dutch windmill at Lawrence, Kansas .... ---·------·----·--------

II. Elevation of apparatus used by Perry in wind-wheel tests ..... _. _ 

III. View of mill No.2 (12-foot Woodmanse Mogul) and anemometer .. 

IV. View of mill No. 3-12-foot Aermotor .... _ ............... ---· .. __ _ 

V. View of mills No.4 (8-foot Ideal) and No.5 (8-foot Aermotor) __ _ 

Vl. Working parts of mill No. 6-8-foot Gem ... __________ - _ ..... _ --· 

VII. View of mill No. 12-14-foot Ideal ............ ------ ___ . __ .. --- VIII. View of mill No. 13-12-foot Aermotor _ .... _. _ .. __________ .. ______ _ 

IX. View of mill No. 19-12-foot Gem_ _ _ _. . .. _ .... __ .... _ .... _ ......... _. _ .. 

X. A, View of mill No. 20-15t-foot Jumbo; B, View of Defender mill 

and "water elevator'' ____ ........ __ .............................. _ ........ . 

XI. View of mill No. 21-12-foot Halliday .. __ .. __ .. _ ... _ .. _ .. _ .. _ ... _ ... -~ 

XII. View of mill No. 35-8-foot Dempster .... ___ .. _____ . _____ .... __ ... __ _ 

XHI. View of mill No. 42-6-foot Ideal ... __ .............. __ . ____ . _ .. _ .... ____ .. 

XIV. View of mill No. 48-30-foot Halliday_ .. _ ...... _ .. _. _ ...... _.. _ ...... _ .. 

FIG. 1. Section of common European post windmill mounted on central 

column ...... __ .... _ .. _ .................. _ ............. " .............. -.-- .... -- --.--

2. Early form of head of European tower windmill.------·----------

3. View of Gause pump ........ __ ... _. __ ....... ______ .---·. ------------

4. Working parts of W oodmanse Mogul . _ ... __ . _. ______ .. _________ . 

5. Sectional view of Woodmanse pump ........... _____ . _____ ....... .. 

6. Diagram showing results with mill No. 2-12-foot Woodmanse 

Mogul ..... ___ .. _____ . __ ..... _____ . _____ ..... __ .... __ ....... ____ .. ____ . ___ .. _ 

7. Working parts of Aermotor .. ____ ... _ .. _ .. __ . ____ ... ______ -. - .. _ . _ . 

8. View of Stone pump ___ . ____ . ___ ----- _________ ... __ -----. --· .... __ 

9. Details of Stone pump _ .. _________ . ______ ... _ .... ___ .. _ . _. _ .... _. _ .. _ .. 

10. Diagram showing results with mill No. 3-12-foot Aermotor _ . __ . _ 

11. Diagram showing results with mill No. 4-8-foot Ideal _ ..... _ .. __ -

12. Diagram showing results with mill No. 5-8-foot Aermotor .. ------

13. Diagram showing results with mill No. 9-16-foot Aermotor __ .. __ 

14. Working parts of mill No. 11-12-foot Ideal ______ ......... __ --------

·15. Diagram showing results with mill No. 11.. ______ ..... _____ ·--- .... 

16. Working parts of Frizell cylinder ..... _ .... _. ___ . _ . __ .......... _. ____ .. _ 

17. Diagram showing results with mill No. 12-14-foot IdeaL ..... ___ .. -

18. Diagram showing results with mill No. 19--12-foot Gem ....... _ ... _ 

19. Diagram showing results with mill No. 20--15t-foot Jumbo .. _. __ _ 

20. Working parts of Halliday mill ................... _ .............. _ .. __ . __ _ 

21. 'Diagram showing results with mill No. 21-12-foot Halliday ...... __ 

22. Diagram showing revolutions of wind wheel of mill No. 30-16-

foot Irrigator .. _ . .. . . .. _ ... _ ....... ___ ................. _ ...... _ .. _. _ .. _ . __ .. __ .. 

23. Diagram showing horsepower of mill No. 30. _ .. ___ - __ - _ .... __ ~ .. --

7 

• 

Page. 

14 

20 

28 

30 

32 

40 

42 

42 

44 

46 

46 

52 

58 

60 

12 

13 

24 

26 

27 

28 

29 

30 

31 

32 

32 

33 

36 

38 

39 

40 

41 

45 

46 

47 

48 

49 

.50 
8 ILLUSTRATIONEJ. 

Page. 

FIG. 24. Comparative diagram showing results with mills No. 35 {8-foot 

Dempster) andNo. 36 (22~-footEclipse) ------------------------- 53 

25. Pump. pressure-tank. and hydraulic regulator of mill No. 37--12-

foot W oodmanse Mogul _____________ . ________ . .. _ .. __ . __ . __ . _.- 54 

26. Diagram showing results with mill No. 37------- ______ .... ____ ·--- 55 

27. Comparative diagram showing results with mills No. 38 (10-foot 

wooden Woodmanse) and No. 48 (30-foot wooden Halliday)_____ 56 

28. View of mill No. 43-10-foot Perkins _. __ .. ___ . ____ . _ .. _ ... ___ .. _. 58 

29. WorkingpartsofmillNo. 51-8-foot:Monitor- ____ . -------------- 62 

30. Diagram showing relation between horsepower and wind velocity 

for five 12-foot mills .. _. _ ... _. _. ___ . ________ . _. __ . ______ ... ___ . _ 66 

31. Diagram showing relation between horsepower and wind velocity for four 8-foot mills _________________ . __ ... _ _ _ __ . ____ .. __ •. ____ . 67 
LETTER OF TRANSMITTAL. 

DEPARTMENT OF THE INTERIOR, 

UNITED STATES GEOLOGICAL SURVEY, 

DIVISION OF HYDROGRAPHY, 

Washington, December 5, 1900. 

SIR: I have the honor to transmit herewith a manuscript entitled 

The Windmill: Its Efficiency and Economic Use, Part I,· by Edward 

Charles Murphy, formerly professor of civil engineering at· the University of Kansas, an,d to request that it. be published in the series 

of Water-Supply and Irrigation Papers. 

This paper, with its complement, Paper No. 42, is a revision of 

Paper No. 8, printed in 1897, embodying additional data obtained by 

recent investigations. The demand for Paper No.8 was so great and 

the practical applications of windmills to the problem of bringing 

water to the surface have been so extended that it has seemed desirable 

to make available the cdnclusions given in the following pages. 

Very respectfully, 

Hon. CHA.RLES D. WALCOTT, 

F. H. NEWELL, 

Hydrographer in Charge. 

Director United States Geological Survey. 

9 

THE WINDMILL: ITS EFFICIENCY AND ECONOMIC USE. 

PART I. 

By EDWARD CHARLES MURPHY. 

INTRODUCTION. 

History does not record the name of the person who invented t.he 

windmill, nor give the date of the invention. The belief that windmills were used by t.he Romans is not well authenticated, and their 

use by the Bohemians in 718 is doubted. It is quite clear, however, 

that they were used in France and Italy in the twelfth century for 

grinding corn, and that they were used in Holl~nd in the fifteenth 

century for pumping water over the dikes into the sea. 

Mr. John Burnham, of Connectieut, is said to be the inventor of 

the American windmill. Mr. L. H. Wheeler, an Indian miAsionary, 

patented the Eclipse mill in 1867. The first steel mill was the Aermotor, invented by Mr. T. 0. Perry in 1883. 

The common European windmill, shown in section in figs; 1 and 2, 

differs much in appearance from the American mill. The wind wheel 

of the European mill has usually four long wooden arms, to each of 

which is attached a sail, against which the wind presses. The sails 

consist of a framework, on which canvas is stretched, usually forming 

a warped surface, the angle with the plane of the arms ( call~d .the 

angle of weather) being about 7° at the outer end and u~o at the inner 

end. The lengt.h of sail was usually about five-sixths the length. of 

the arm, the width of the outer end one-third the length, and the 

width of the inner end one-fifth the length. The sail area is seen to 

be small compared with the wind area or zone containing the sails. 

The arms were sometimes 60 feet long. The American wooden mill is 

much smaller and more compact than the European mill. It has six 

or eight arms, to which is attached a framework carrying many small 

sails. These sails are usually 3 or 4 feet long, 3 or 4 inches. wide at 

the outer end, and 1 to 3 inches wide at the inner end, and are set at 

an angle of 30° to 40° to the plane of the wheel. For large wheels 

these sails are arranged in two or more concentric rings. The Ameri11 
12 THE WINDMILL. [No.41. 

can steel mill differs principally from the wooden mill in that it has 

larger and. fewer sails for a given size of mill, its sails are curved 

instead of plane, and it offers less resistance to the passage of the air 

over the back of the sails. In the sails of the steel mill there is seen 

to be a partial return to those of the European mill. 

FIG. 1.-Section of common European post windmill mounted on central column. 

CLASSIFICATION OF WINDMILLS. 

Windmills may be divided into two general classes-paddle wheel 

and sail wheel. The Jumbo shown in Pl. XVI, B (Part II), and Little 

Giant No. 56, described on pages 125 to 127, Part II, are good illustrations of the first class. In both of these mills the sails move with 

the wind~ and it is necessary to have a shield, or a method of feathering 
MURPHY.] CLASSIFICATION OF WINDMILLS. 13 

the sails, in order to keep the wind from striking them when they are 

moving in a direction opposite to that of the wind. In the Jumbo the 

axis of the wheel is horizontal, in t,he Little Giant it is vertical; but 

_the wind acts on the sails of both in substantially the same way. 

The air acts with full pressure on only one sail of the Jumbo at any 

one time, and on half 'the sails it has no action, or only negative 

action. 

In the sail-wheel mill (fig. 1, Part I, and Pl. XV, Part II) the wheel 

moves at right angles to the direction of the wind, instead of in the 

same direction, as in the paddle-wheel mill. •rhe wind acts with a 

FIG. 2.-Early form of head of European tower windmill. 

certain pressure on all of the sails all of the time. The circumference 

velocity of the sail wheel may be two or more times greater than the 

velocity of the wind that, drives it, but the circumferen·ce velocity of 

the paddle wheel is always less than the velocity of the wind that drives 

it. The sails of the sail-wheel mill must be placed at an angle with 

the plane of the wheel, so that the wind will press on them; but the 

sails of the paddle-wheel mill may be iL the plane of the axis of the 

wheel. 

For greatest p•ssure on the sails of a sail-wheel mill the axis of the 
14 THE WINDMILL. [No.41. 

wheel must be parallel to the direction of the wind. It is necessary, 

then,. for the wheel to change its direction as the wind changes. In 

the German or post mill the whole building, as well as the wheel, can 

be turned around on a post by hand. In the tower or Dutch mill the 

upper part only of the mill turns with the wheel. This is accomplishPd 

by hand in the mill shown in fig. 1, and by an auxiliary windmill in 

the mill shown in fig. 2. In the American mills the upper part only 

turns on a turntable, which is usually on rollers or balls. This is 

accomplished, first, by the pressure of the wind on a long rudder 

vane extending out behind the mill, and in some mills by a side vane 

as well; or, second, by the pressure of the wind on the wheel itself, 

which is placed on the opposite side of the tower, as in fig. 46, Part 

II; or, third, by side wheels, as in mill No. 52, fig. 50, Part II. 

REGULATING DEVICES. 

The wind is constantly changing in velocity as well as in direction, 

and if the load on the mill is constant the speed of the mill and of 

the machine which it operates will change with it. If the speed is to 

be kept nearly constant, some device is needed to reduce the wind 

pressure on the wheel when the wind velocity reaches a certain 

amount. In the European mill there are two met,hods of doing this, 

viz, by means of a brake or friction rings and by changing the sail 

area. The latter is accomplished by rolling or unrolling the canvas 

sails by hand or automatically. In the Americau mill the speed is 

regulated by changing the sail area in one of three ways: (a) By sections of the wheel revoldng about an axis which places each sail at 

an angle to the direction of the wind lessthan 90°, as in fig. 36, Part 

II; (b) by placing the axis of the wind wheel eccentric to the axis of the 

tower, so that the wind pressure on the wheel will cause it to revolve 

around the axis of the t.ower; and (c) by the wheel moving naturally around the axis of the tower in the direction in which it is 

revolving. This turning action around the axis of the tower is counteracted by a spring or a weight, or, as we commonly say, "the wheel is 

held in the wind" by a spring or a weight. A weight is better than 

a spring, for by moving it out or in any desired pull can be placed on 

the wheel. A spring can not easily be adjusted and may lose some of 

its tension. The first method of regulation, called the centrifugalgovernor method, is used in the Halliday mill (fig. 20) and in the 

Althouse-Wheeler mill (fig. 36, Part II). The second method is illustrated in the Aermotor (fig. 33, Part II), which shows the axis of the 

wheel eccentric to the axis of the tower by 4.5 inch.es. It also shows 

the spring which holds it in the wind. This spring also resists the 

action of the load, which tends to turn the wind wheel out of the wind, 

The third method is illustrated by the W oodmanse mill. 

• 
U. $. GEOLOGICAL SURVEY WATER-SUPPLY PAPER NO. 41 PL. I 

DUTCH WINDMILL AT LAWRENCE, KANSAS. 
l\IURPHY.] EARLY EXPERIMENTS. 15 

EART.1 Y EXPERIMENTS. 

Smeaton's experiments.-The first experiments of which we have 

any record were made by John Smeaton, an English engineer, and 

published in 1755 to 1763. 1 These experiments were made on model 

windmills of the European type, for the purpose of. determining the 

best shape of sail for a given sail area. The models each had four 

arms 21 inches long. For one set of tests the sails were 5.6 inches 

broad and 18 inches long, giving an area of 403 square inches. In 

another set of tests the sails were 18 inches long, 5. 6 inches wide at 

the inner end and 8.4 inches wide at the outer end, with an area of 504 

square inches. The sails were either plane or warped at various angles. 

These mills were worked by moving the windmill around in a circle of 

5f feet radius, in still air, instead of placing them on a tower and allowing the natural wind to drive them. The wheel was moved around in 

this circle by means of a cord wound on a clrum on a vertical shaft, 

the horizontal arm which held t,he wheel being fastened to this shaft. 

The work done by the wheel in a given time was measured by observing 

the length of string wound on the shaft of the wheel, a weight of 

known size being attached to the end of the string. The velocity of 

the wind, which was assumed to be the velocity of the end of the arm 

where the wheel was attached to it, varied from 4! to 8! feet a second, 

or from 2. 9 to 6 miles an hour. 

It will be noticed that these wheels are only 3. 5 feet in diameter, 

that they were moved in a circle only 5.5 feet in diameter, and that 

wind velocities or wheel velocities were small and of only a limited 

range-from about 3 to 6 miles an hour. Smeaton draws the following conclusions from his experiments: 

( 1) The velocity of the windmill sails, whether unloaded, or loaded so as to produce a maximum, is nearly as the velocity of the wind: their shape and position 

being the same. 

(2) The load at the maximum is nearly, but somewhat less than as the square 

of the velocity of the wind: the shape and position of the sails being the same. 

(3) The effects of the same sails at a maximum are nearly but somewhat less 

than as the cubes of the velocity of the wind. 

( 4) The load of the same sails at the maximum is nearly as their squares and 

their effects as the cubes of their number of turns in a given time. 

(5) When the sails are loaded so as to produce a maximum at a given velocity 

of the wind, and the velocity of the wind increases, the load remaining the same: 

first, the increase of effect, when the increase of the velocity of the wind is small, 

will be nearly as the squares of those velocities; secondly, when the velocity of 

the wind is doubled, the effects will be nearly as 10 to 27 .5; but, thirdly, when the 

velocities compared are more than double of that where the given load produces 

a maximum, the effects increase nearly in a simple ratio of the velocity of the 

wind. 

(6) If sails are of similar figure and position, the number of turns in a given 

time will be reciproca1..ly as the radius or length of the sail. 

1 Philos. Trans. Royal Soc. London, 1700-1763, -
16 THE WINDMIIJL. [No.41. 

(7) The load at a maximum that sai.ls of a similar figure and position will overcome at a given distance from the centre of motion, wiH be as the cube of the 

radius. 

(8) The effects of sails of similar figure and positiqn are as the square of the 

radius. 

(9) The velocity of the extremity of Dutch sails, as well as of enlarged sails, in 

all their usual positions, when unloaded, or loaded to a maximum, is considerably 

quicker than the velocity of the wind. 

Regarding the ratio of the sail area to the wind area or zone containing the sails, he found that where the ratio was greater than 7 to 8 the 

power of the mill was decreased instead of increased. Regarding the 

proper shape of sail, he found that the warped sail was more effective 

than the plane sail. He also found the following six angles of weather 

at equal distances from the shaft outward adv-antageous: 70°, 71 o, 72°, 

7 4 o, 77.5°, and 83°. He states that a difference of two or three degrees 

in the angles of impact makes little difference in the power of the 

mill. 

Coulomb's experiments.-C. A. Coulomb, a French engineer, made 

some tests of the work done by a Dutch windmill used for extracting 

oil from rape seed at Lill~, in Flanders. His observations were published in 1821. 1 The mill was 70.2 feet in diameter. It had four 

warped canvas sails, each 28.7 feet long and 6.6 feet wide; the width 

of canvas was 5.5 feet. The angle which the plane of sail made to 

the plane of the wheel varied from 30° at the inner end to 12° at the 

outer end. The wind velocity was measured by the use of feathers 

carried along by the wind. Two men were stationed 150 feet apart, 

on slight elevations, to note the time required for each feather to pass 

over this distance. The velocity of the wind striking the wind wheel 

was assumed to be that found from these feathers. In a 14. 9-mile 

wind, and with the load ordinarily used, he found that the wheel made 

13 revolutions per minute with all the canvas spread. From these 

data he figured the useful work done by the mill per minute to be 

232,388 foot-pounds and the useless work expended in shock of stampers and fric-tion to be 37,310 foot-pounds, or a total of 269,698 footpounds, equal to 8.17 horsepower. 

Coulomb did not consider this a complete or satisfactory test of 

this mill. He did not control the working of the mill, but simply 

observed what it did wp.en handled by the miller who extracted the 

oil. He tried to ind nee the owner to permit him to use the mill for a 

time for experimental purposes, but did not succeed. 

It will be seen from what follows that even if we assume the wind 

velocity to be correctly measured, this test does not necessarily show 

the power of the mill, for we do not know that the load used was the 

proper load for the wind velocity. It shows what the mill was doing, 

not what it might do under a better loading. 

1 Theorie de Machines Simple, by C. A. Coulomb. Paris, 1821.. 
MURPHY.) EARLY EXPERIMENTS. 17 

Grfjfiths's experiments. 1-In 1891-92 Mr. J. A. Griffiths made tests 

of six windmills used for raising water, with the following results: 

Results of Wtndmill tests by J. A. Griffiths. 

s ..... dJ .... '14 .... .... 'd 1=!14 ""'14 

~·m 0,...; i=IQJ. 0 0 c.e 0~ OQJ Oal 14 c,e'"" a~ t.eaJ aS~~ Q)..; p. p...o Q) 

;a~ c.ec.e Q)Q) pt.e i4P, alp, ~ ~Q) e . ~ 

Of windmill .... w. 14~ 14om 

~~ 'd .:SJ.i t'.-o~ >. $ 0 .... 'd.,_. c.er::: ~~~ ~a ..t:<~S tested. 140 140 sg. c.ef::: 'g.~ 8 ;;::- ::l p, 00. 

~~'g QJI4 Qll4 oP c.eEl:> g::::.s gj ~~ 14p, 14.,_. ...-Q) 

p'-' i=!al ~0 0 g.~ Qit:::..2 Q) as ~ ~~ ~t>Jl<D -~ """ l=lp OaJ 1-j Q w. <11 ..-::! > > lil --------- ------------

Feet. Feet. Sq. ft. 0 I In. In. Feet. Ft.-lb.~. Miles. Ret'. 

1 Toowoomba ________ 22.3 8.3 39:20 18 47 5 6. 75{ 25 .120 4.3 5.0 0.018 

100 480 7.0 6.8 0.098 

2 Stover __ ------------ 11.5 4.5 104.0 43 3 4{ 29.2 29.2 5.8 13.0 0.011 

61.2 61.2 6.5 13.3 0.025 "I Perkin•----- _______ 16.0 6.0 201.0 36 3 10.75 39.0 105.0 6.0 7.5 0.024 

~ -~~~~~~~~--~-~~~-~~~= 14.2 4.5 157.0 30 3 c10 66.3 166.0 7.0 12.6 0.065 

10.2 3.8 81.0 28 3 H 38.7 51.0 8.5 20.5 O.ll'.?S 

6 Carlyle------------- 9.8 4.2 80.0 50 3 4 30.7 30.7 6.0 12.5 0.012 

a These pump loads have been computed for comparison of these results with others. 

bAt maximum efficiency. c Pump is double acting; this is twice the limgth of stroke. 

No. 1 was a 22.5-foot wooden mill, with 20 warped sails each 87 by 

36 by 9 inches, t.he weather angle at the outer end being 18° 47' and 

at the inner end 40° 20'. It worked a direct-acting single-stroke pump 

having a 5-inch cylinder and 6. 75 inches stroke. Two lifts were used, 

one of 25 feet and the other of 100 feet. 

No. 2 was a 12-foot Stover wooden mill, having a wind wheel somewhat like that of mill No. 38. It had 112 sails, each 43 by 3.75 by 1.5 

inches, set at an angle of 43° to the plane of the wheel. It worked a 

direct-acting single-stroke pump having a 3-inch cylinder and 4 inches 

stroke. The lifts were 29.2 and 61.2 feet. 

No. 3 was a 16-foot Perkins solid wood wheel, the wind wheel having 160 sails, each 60 by 4 by 1.5 inches, set at an angle of 36° to the 

plane of the wheel. It worked a direct-acting double-stroke pump 

having a 3-inch cylinder and 5.375 inches stroke. The lift was 39 

feet. 

No.4 was a 14-foot Althouse-Wheeler wooden sectional mill, the 

wind wheel having 104 sails, each 48 by 4 by 1.5 inches, set at an angle 

of 30° to the plane of the wheel. It worked a direct-acting doublestroke pump having a 3-inch cylinder and 5 inches stroke. The lift 

was 66.3 feet. 

No. 5 was a 10-foot Althouse-Wheeler wooden sectional mill. The 

wind wheel had 84 sails, each 38 by 3. 75 by l .5 inches, set at an angle 

of 28° to the plane of the wheel. It worked a direct-acting singlestroke pump having a 3-inch cylinder and 4.625 inches stroke. The 

lift was 38. 7 feet. 

No. 6 ·was a 10-foot Carlyle iron mill. It had 7 somewhat spoonshaped sails, each having a spout-like extension through which t,he 

1 Windmills for raising water, by J. A. Griffiths: Proc. Inst. Civ. Eng., Vol. CXIX, p. 321, 

IRR 4:1-01--2 
18 THE WINDMILL. [No.41. 

ail! flowed. It worked a direct-acting single-stroke pump having a 

3-inch cylinder and 4 inches stroke. The lift was 30.7 feet. 

The wind velocity was measured with the "f" wind gage, which 

was either on a tower near by or on an arm projecting as far as possible to windward. It ~ppears that it was necessary to be near the 

ga1rP- in order to read the velocity, which would indicate a possible 

error in wind velocity and some interference with the wind striking 

.the wind wheel. rrhe range of wind velocities is not stated, and not 

more t.han two loads were used in any case. 

These results will be compared with others further on. 

King's experirnents. 1-Prof. F. H. King conducted a series of experiments with a 16-foot geared Aermotor, covering a period of one yearfrom March 6, 1897, to March 6, 1898. This mill was used to work 

one or more of four pumps: (1) A reciprocating piston pump with a 

14.;inch cylinder and 9 inches stroke; (2) a bucket pump having a 

normal capacity of 120 gallons per minute; (3) a No.2 Gould centrifugal pump; and (4) the smallest size Menge pattern centrifugal pump. 

The ht;J.Cket pump was used nearly all of the time. The reciprocating 

piston pump was used occasionally by it.self and part of the time with 

the bucket pump, when the wind velocity was strong enough to carry 

both. The :Menge was used occasionally with the piston pump and the 

bucket pump, when the wind velocity was strong enough to carry all. 

There was no automatic device for throwing into or out of use any 

of these pumps. It was necessary to do this by hand, so that a part 

of the time the load on the mill was not suited to the wind.velocity. 

This can be seen from the record. For example, on February 10, from 

1 to 7 p. m., the wind velocity varied from 9 to 12 miles an hour and 

8.6 tankfuls of water were pumped, while on June 1, from 8 a. m. to 

4 p. m., the wind velocity varied from 11 to 15 miles an hour, and not 

a tankful was pumped. The report gives the number of tankfuls of 

141.2 cubic feet which were lifted 12.85 feet each hour during the year, 

and some interesting conclusions drawn from tht>se records. 

Professor King has also made some tests of this mill with a Prony 

friction brake. The results of these tests, and the indicated horsepowers computed from them, are as follows: 

1 :Bull. No. 681 Wi~onsiu Agricultural Experiment $ta.tion. 
MURPHY.] EARLY EXPERIMENTR. 19 

Results of tests of 16-foot geared Aermotor. 

Wind Indicated .Average Average velocity Direction Temperaof wind. horse- wind horse- Barometer. 

per ture. power. velocity.· power. hour. 

---

Miles. Miles. Inches. Degrees. 

8.4 sw. 0. 2715 8.4 0.2715 29.40 0.0 

12.·0 ... --------- 0.5791 } { 29.36 0.5 

12.4 ---------- 0.7230 12.33 0.5858 29.36 0.5 

12.6 ... -... __ .. ---- 0.4553 29.36 0.25 

13.2 sw. 0.6213 13.2 0.6213 29.40 0.5 

14.6 sw. 0.7343 } { 29.36 -0.5 

14.6 ---------- 0.9449 14.68 0.8602 29.40 0.5 

14.8 sw. 0.9016 29.40 1.0 

18.6 NW. 2.054 

I} 18.70 1.873 

1 

28.86 9.0 

18.8 sw. 

I 

1. 692 29.40 1.0 

21.2 sw. 2.593 29.40 1.5 

21.6 w. 3.715 } 21.55 3.033 29.06 -2.0 

21.6 N. 3.227 28.86 7.0 

21.8 NW. 2.597 ------- ____ ,.,.. ___ 

I 22.0 w. 4.326 ) { 29.09 1.0 

22.0 w. 4.236 22.06 3.652 29.04 -2.0 

22.2 NW. 2.394 ------- ---------- 23.0 w. 3.842 } 23.00 3.996 f 29.07 -1.0 

23.0 w. 4. l!ll t 29.05 -1.0 

24.0 ----- '---- 5.983 } 24.30 4.768 { 28.75 6.8 

24.6 w. 3.554 29.09 1.5 

25.2 w. 4.882 25.2 4.882 29.09 1.5 

27.3 N. 4.092 } 27.16 4.471 { 28.66 6.3 

l! w. 4.850 29. 10 1.5 

0 N. 5.953 39.0 5.953 28.69 6.5 

0 -------· -- 5. 971 40.0 5.971 28.69 6.3 

This mill is similar to our.16-foot Aermotor No. 44, described in Part 

II. lt"will be seen later that the power found by Professor King is much 

greatert.han we have found it for high wind velocities. The probable 

reason for this difference will be discussed later. It may be stated here, 

however, that Professor King measured the wind velocity with an 

anemometer in a fixed position 40 feet due east of the windmill, and 

it will be seen that the wind was from the west, northwest, or southwest nearly all of the time when the brake tests were being made. 

(The wind came from the north around by the east to the south only 

three times while the brake tests were in progress.) The revolving 

wheel must have interfered with the running of the anemometer and 

caused it to show a less wind velocity than really existed. 

Professor King also determined the work done by the mill in grinding corn. r.rhe power of the mill in a given wind velocit,y can not, 

however, be judged from these tests, since the grinder load was 

probably not suited to all wind velocities. 
20 THE WINDMILL. 

Results.of brake tests of 16-foot geared Aermotor. 

Wind velocity per hour. 

Indicated 

horsepower. 

Wind velocity per· hour. 

[N0.41. 

Indicatedhorsepower. 

Smiles ________________ 0.25 26miles .. --------·---- 4.82 

10miles ____ -____________ 0.40 28miles ___ -----------· 5.14 

12 miles ________ ·---____ 0.56 30 miles .... -----··----_ 5.40 

14 miles. _____ ._________ 0. 78 32 miles.________________ 5. 61 

16 miles ___ . __________ .. _ 1. 08 34 miles._ .. _ _ _ _ _ _ _ _ _ _ __ 5. 76 

18miles________________ 1.62 36miles _____ . _______ 5.87 

J_

_2_0_m_il __ e_s _________________ --_-_-_-_--_,___2_._3_9---"--3-S_m_il_e_s __ -_·_-_-_________________ -- -_.____:j' 95 22 miles 7 . _________ . _ _ _ _ _ 3. 31 40 miles .. __ •... ______ ... 24 miles ____ .•...• _. _ _ _ _ 4. 31 

Perry's exper;-·iments.-From June, 1882, to September, 1883, lVIr. 

T. 0. Perry made experiments with 61 windmills, each 5 feet in 

diameter. The results were published in 1889. 1 Mr. Perry's methods 

were similar to those employed by Smeaton-he used small wheels 

moved against still air in a circle of 14 feet radius. His experiments 

were made on a much larger scale than Smeaton's, however, and-his 

apparatus was more perfect. Smeaton used wheels of European type; 

Mr. Perry used those of American type. Pl. II is an elevation of Mr. 

Perry's apparatus, showing the wheel as it revolved about, the vertical 

shaft, driven by an 80-hm·sepower engine. The power was measured 

by means of a Prony friction brake placed on a brass cylinder on the 

wind-wheel shaft. In order to eliminate the effect due to differences 

in the condition of the air, and get results comparable with one 

another, lVIr. Perry used one of his wheels as a standard with which 

to compare the others. After the best load for a wheel had been 

obtained, comparative tests were made with this one and with the 

standard wheel, by trying first one wheel and then the other until 

several measurements of ea~h had been taken. The final result of 

each wheel was the average of eight or ten measurements. 

In comparing Smeaton's results with his own, Mr. Perry writes: 

We were not able to obtain the best results with weather angles as small as 

Smeaton's in any of our wheels. Nor did our sail speeds, as compared with wind 

velocity, nearly approach the speeds obtained by Smeaton. Even our unloaded 

wheels did not show the sail speed attained by the best of Smeaton's when loaded 

for maximum work. * * * Our loads at the maximum of work were sma-ler 

as compared with the greatest loads, and the speed of revolutions at maximum 

work as compared with the speeds of unloaded wheels, were smaller for our mills 

than for Smeaton's. 

He states, how~ver, that the general conclusions drawn by Smeaton 

(see pages 15 to 16) were substantially confirmed by his experiments. 

The difference between his results and Smeaton's he attributes to thPt 

differences in the mills used. 

l Water-Supply and Irrigation Paper U.S. Geol. Survey No. 20. 
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER NO. 41 PL. II 

:SCALE 

2 3 

ELEVATION OF APPARATUS USED BY PERRY IN WIND-WHEEL TESTS, 
MURPHY.] WRITER'S EXPERIMENTS. 21 

Some of Mr. Perry's conclusions are as follows: 

(1) There is nothing gained by having the sail area more than seveneighths of the wind area, and there is little gained by having it more 

than three-fourths of the latter area. 

(2) That the power varies as the cube of the wind velocity. 

(3) That the load for maximum power varies as the square of the 

wind velocity. 

( 4) That the speed of the unloaded wheel increases somewhat faster 

than the wind velocity. 

(5) That the best speed for most of his wheels was about 0~55 per 

cent of the unloaded speed. 

( 6) That the conical deflector at the center of the wheel does not 

increase the power. 

(7} That obstructions on the back of sails greatly reduce the power 

of the mill. 

(8) That the speed of wheel No. 48 was increased 48 per cent by 

removing the strip from the back of each sail. 

(9) That a deflector in front of the wheel increased the speed of a 

slow-moving wheel. 

(10) That a deflector in front of the wheel did not increase the speed 

of a rapidly moving wheel. 

(11) That a mast offers .more obstruction in front of a wheel than 

uehintl it. 

EXPERIMENTS BY WRITER. 

The tests of wind wills described in the following pages were begun 

by the writer in the summer of 1895. They were continued during 

the summer of 1896, with much better facilities than during the previous season. The results obtained to that time were published in 

Water-Supply and Irrigation Paper No. 8, entitled Windmills for 

Irrigation. Since then the work has been continued as time could 

be spared---=mainly during a portion of three summer vacations. 

The work of the summer of 1896 was confined mainly to pumping mills. The tests show what each windmill and its pump were 

actually doing under certain conditions of load, lift, etc. They do 

not show what the mill might do under othe1· conditions. It was evident that the useful work of a mill varied with its load and the 

efficiency of the pump. The latter could not well be ascertained. It 

was, therefore, thought best to confine the tests principally to 

power mills, in which the unknown factor of pump efficiency is not 

present, and where the load on the mill can easily be varied. This 

has enlarged the scope of the work, making it cover windmills for 

power as well as those for irrigation. 

Many of our tests of pumping mills were made in the vicinity of 

Garden, Kansas. Perhaps nowhere in the United States is irrigation 

from wells by the use of windmills carried to the same extent as there, 
22 THE WINDMILL. [:No.41. 

where may be found hundreds of windmill pumping plants furnishing 

water to irrigate from 1 to 15 acres each and lifting from 3 to 14.5 

quarts per stroke to a height of from 10 to 45 feet, as well as large 

steel mills running day ·and night, when. the wind is strong enough, 

and working pumps of the best kind. 

SCOPE OF TESTS. 

There .are many makers of American windmills, and with the g1·e~t 

variety of mills in use-no two are alike, though in some cases the 

difference is slight-it was impossible to test a mill of each type. It 

was our purpose to test only the mills that were in good working order 

·and subject to good wind exposure, and which would add new data to 

that already obtained or confirm in some particular that previously 

secured. In some cases two or more mills of the same size and make 

were tested to show as far as possible the effect of pump, well, etc. 

on the useful work. The parts of mill and pump on which the power 

depends were carefully measured. The t,emperature and barometric 

pressure were observed in each case and the mean given. The discharge of pump per stroke was measured when possible, and the 

diameter of cylinder and length of stroke are given, so that the discharge can be compared with the figured displacement. The lift was 

measured whenever the surface of the water in the well could be 

reached with a tapeline. ·The number of strokes of the pump per 

mile of wind was found for velocities from 6 or 8 miles to 20 or 30 

miles an hour. In some cases the number of strokes is given when 

no water was being pumped. In fact, there was collected for each 

mill as much data as it was conveniently possible to obtain which 

would in any way affect the power of the mill or be of interest. 

PUMPING MILLS. 

The essential difference between pumping and power mills is that 

in the former there is a pump rod with an up and down motion, while 

in the latter there is a vertical rotating shaft. The former is usually 

geared back 2 or 3 to 1, while t.he latter is generally geared forward 

6 or 8 to 1. The ordinary pumping mill, such as is used for stock 

purposes, is lighter than the power mill, but the irrigating mill is of 

nearly the same weight as the power mill. The larger power mills 

have a pumping attachment, so as to work a pump as well as a 

grinder or -other machine. 

WELLS NEAR GARDEN, KANSAS. 

A brief description of the water supply and wells of this locality 

may be helpful in considering what follows. 

The water is found in sand and gravel at distances below the surface varying from 8 to 40 feet. This material is in layers of variable 

thickness and different degrees of coarseness, ranging from fine sand 
MURPHY.] WRITER'S EXPERIMENTS. 23 

to large gravel. It is overlain by a layer of sandy clay, which in 

some places will for years stand vertical without any support; in 

other places there is very little clay in this layer. The wells are 

usually 3 to 4 feet square, and are cased with wood through_ the top 

sandy clay to the water-bearing sand; then a wood or galvanized-iron 

casing from 12 inches to 3 feet in diameter extends down from 8 to 20 

feet into the sand to a layer of gravel. Where this latter casing is 

large, three or more galvanized-iron pipes 6 to 12 inches in diameter 

are put down in the bottom {)f it~ and these sometimes have wire 

gauze over their tops to keep down the sand; they also have perforations about one-fourth of an inch in diameter for a distance of 2 ff;'et 

or mQre from the bottom to admit the water. In many cases, instead 

of this small open well, the supply pipe is on a well point having the 

same diameter as the supply pipe, its length varying with t~e diameter. These well points have not given satisfaction and are being 

replaced by open wells. 

On examining well points that have been used for a ttme it was 

found that many of the little openings through which water is admitted 

to the pump had become filled with fine grains of sand, thus reducing 

the area. Although this water area was of the proper amount when 

the well was new, it becomes too small after the well has been used 

for a time or after it has stood without being used. If this area is too 

small to allow the free passage of water into the pump, an added 

load is put on the latter. 

PUMPS. 

Nearly all of the pumps in use in the vicinity of Garden are of the 

reciprocating-piston type. Fig. 8 shows the Stone pump, manufactured by R. G. Stone, of Garden. This pump is made in three sizes6 inch, 8 inch, and 10 inch, these dimensions being t.he approximate 

diameter of the discharge pipe. The diameter of the cylinder is less 

than the diameter of the pipe by twice t.he thickness of the brass lining. The valves (shown in fig. 9) are of the latest pattern. The 

plunger valve is of the single-flap or clack variety and the check 

valv~ is of the disc variety, made so that the water can pass up the 

center as well as around the sides. In an earlier form of this pump 

the plunger valve is of the double-flap or butterfly type and t.he check 

valve of the lift type, but with no opening at the center. Probably 

nine-tenths of the pumps in use near Garden are of the Stone variety. 

Fig. 3 shows the Gause pump, one of the first pumps used there for 

irrigating purposes. It is more expensive than the Stone pump, and is 

not now so much used. Fig. 16 shows the cylinder of an 8-inch Frizell 

pump, a few of which are in use. Fig. 5 is a sectional view of the 

Woodmanse pump, which is used with mill No; 2. Pl. X, B, shows 

a crude homemade pump called the "water elevator." One of these 

is in use in Garden. 

The efficiency of reciprocating pumps like those described varies 
24 THE. WINDMILL. [:No.41. 

directly with the lift. inversely with the number·of strokes per minute, 

and with the design of the pump. For lifts of 10 or more feet and not 

more than 30 strokes per minute the efficiency in a good pump should 

be at least 70 per cent. 

Prof. 0. P. Hood 1 has measured the efficiency of two Frizell pumpsone 6 inch, with 14.1 inches stroke, like that 

N shown in fig. 16, and one 4 inch, with 24 inches 

s 

FIG. 3.-Gause pump. N, 

plunger; B, spout; F, discharge pipe; H, plunger; 

T, cylinder; Z, enlarged 

valve opening and check 

valve; S, suction pipe. 

stroke, having a butterfly discharge valve. He 

found that for a 7. 7-foot lift the efficiency of 

the 6-inch pump dropped from 75 per cent to 63 

per cent as the number of strokes increased 

from 10 to 60 per minute; that for a 22. 7-fo9t lift 

it decreased from 86 per cent to 82 per cent for 

the same range of speed; and that for a 37.8-foot 

lift it decreased from 84 per cent to 82 per cent, 

while the number of strokes increased from 10 

to 50 per minute. The efficiency of the 4-inch 

pump dropped from 66 per cent to 60 per cent 

for a 12.8-foot lift, and from 83 per cent to 73 

per cent for a 37.6-foot lift, as the number of 

strokes increased from 10 to 50 per minute. 

The valve area should be not less than 30 per 

cent of the cylinder area. The cylinder should 

be placed as near the water as possible; if it is 

more than 25 feet above the water, and the 

number of strokes is 30 or more, the cylinder 

will not fill properly, and pounding will result. 

INSTRUMENTS AND METHODS. 

The wind velocity was measured with a United 

States Weather Bureau cup anemometer, each 

mile of wind being recorded electrically by one 

pen of a 2-pen register. By means of a little 

device fastened to the pump an electric circuit 

is closed at each stroke of the pump and a record 

made by a recorder. Another electric circuit, 

leading from the recorder to the other pen of 

the register, is closed at each hundred strokes 

of the pump and a record made on the register. 

Hence the graphic record of the register shows 

the number of miles of wind in any given time, also the number of 

hundred strokes of the pump in the same time. The anemometer 

was held on a pole at the height of the axis of the wheel of the windmill. The pole was made so that its length could be increased at 

will from 25 to 50 feet. The anemometer on the pole is shown in Pls. 

III and XI. 

1 Water-Supply and Irrigation Paper U. S. Geol. Survey No.14. 
MURPHY.] WRITER'S EXPERIMENTS. 25 

The discharge of the pump per stroke was ascertained by catching 

the water for several strokes in a tub and measuring it with a quart 

measure. In a few cases it was found to vary with the number of 

strokes per minute. Where it varied the discharge given is for a 

nearly maximum speed of pump. 

The lift, or distance from the surface of .the water in the well 

to the center of the water column as it leaves the discharge pipe, 

was measured when the pump was working quite rapidly. For 

pumps on well points it was estimated from the depth to water when _ 

the point was put down, making an allowance for the lowering of 

the water. 

Each mill tested is described and the=~ results of the tests given in 

tabular form. Nearly all of the mills are illustrated. 

The number of strokes of the pumps per mile of wind and the horsepowers of the mills are in most cases explained by diagrams, which 

show at a glance the facts which otherwise can be comprehended only 

by a careful analysis of the tables. In these diagrams (figs. 6, 10, 11, 

12, 13, 15, 17, 18, 19, and 21) the relation between the wind movement, in miles per hour, and the number of strokes made by the 

pump while the wind was moving over 1 mile is shown by the curved 

line. The space from left to right is proportional to the number 

of strokes of the pump. The data expressed by these diagrams 

were obtained directly from the record given by the anemometer 

register. 

In explanation we will assume that the pen connected with· the 

anemometer makes three short marks· (3 miles) in fifteen minutes, 

indicating a mile in five minutes, or at the rate of 12 miles an hour. 

At the same time the other pen connected with the pump, and registering each 100 strokes, makes, say, two short marks, showing that 

the-pump has made 200 strokes for this-3 miles of wind movement, 

or 67 strokes to the mile. This fact is entered on the diagram by 

a small circle placed at a distance from the right which corresponds to a wind velocity of 12 miles an hour, and at a distance from 

the bottom which corresponds to 67 stro-kes of the pump. In this way 

each observation is indicated. When the points have been plotted, 

the smooth curve is sketched so as to occupy an intermediate position 

among them. 

In order to obtain the number of strokes more accurately than by 

measurement on the register sheet, they were actually counted for 

. a considerable number of observations in each test. The number of 

strokes per minute is obtained by dividing the number of strokes per 

mile of wind by·the number of minutes required to make the mile. 

For example: If the number of strokes per mile in a 12-mile wind 

(which requires 60 -:- 12, or five minutes to make a mile) is 90, then 

90 + 5=18, the number of strokes per minute. The number of gallons raised per minute is found by multiplying the number of gallons 
THE WI:NDMitt. (NO. 41. 

per stroke by the number of strokes per minute. The horsepower of 

the mill in any wind velocity is found by multiplying the number of 

FIG. 4.-Working parts of Woodmanse Mogul. 

gallons per stroke by the number of strokes per minute, .then by 8.3 

pounds (the weight of one gallon of water), then by the lift, in feet, 
MUll.PHY.] PUMPING MILLS TESTED. 27 

and dividing the product by 30,000 (the number of foot-pounds in a 

horsepower), or by the following formula: 

Horsepower= nqgh + 33,000, where n =number of strokes per 

minute, g = the weight of 

one gall~n of water, q =the 

number of gallons per stroke 

of pump, h = the lift, in feet. 

The pump load is the weight 

of water lifted per stroke 

multiplied by the lift, or 

height to which it is raised. 

The number of revolutions 

of the wind wheel per min u t.e 

is found by multiplying the 

number of strokes per minute by the number of revolutions per stroke. 

!'UMPING MILLS TESTED. 

Mill No. 1.-The tests of 

this mill wet·e preliminary 

or experimental, being made 

for the purpose of perfecting 

the instruments employed, 

and were not completed for 

discussion. 

Mill No. 2. -This is a 

12-foot W oodmanse Mogul, 

manufactured by the Woodmanse-Hewitt Manufacturing Company, of Freeport, 

Illinois. Pl. III shows the 

mill, towN·, pump, and pond, 

and :fig. 4 the working parts. 

The tower is of steel, 50 feet 

high to the axis of the wheel. 

The wind exposure on the 

north is not good, the mill 

being 115 feet south of a 

large barn. The wheel has 

30 curved sails, each 36 by 13 

by 5. 5 inches, 1 set at an angle 

of 30° (angle of weather) with 

the plane of the wheel. It is 

back·geared, 3 to 1, and held 

l<'ro. 5.- Sectional view of W oodmanse pump. 

in the wind by a spring. 'l'he pump 

1 In this expression 36 is the length of the sail, 13 the width of sail at the outer end, and 5.5 

the width of sail at the inner end. 
28 THE WlND:MILL. [No.41. 

alRo is of 'Voodmanse make, and is shown, in section, in fig. 5. The 

cylinder is 9.5 inches in diameter, the supply pipe 5.625 inches in 

diameter, the length of stroke 12 inches. The well is 3-! feet by 

3-! feet to the water, a distance of 14 feet. At that point a 12-ineh 

galvanized-iron pipe is put down 20 feet, forming a small 9pen well. 

The lift at the time of test was ~7! feet and the discharge per stroke 

14t quarts .. The mean barometric pressure was 26.98 inches, and the 

mean temperature 94° F. The cost of mill, tower, pump, and well 

was about $210. The results of the tests are asfollows: 

Results of tests of mill No. 2-12-foot W oodrnanse .1Wogttl. 

[Load per stroke, 536.2 foot-pounds.] 

I Wind velocity pe• bon•. 

Revolutions Strokes of Gallons u of wind wheel pump per pumped per hors per minute. minute. minute. 

seful I 

epower. 

I 

I 

12 miles _ _ _ _ _ _ _ _ _ _ __ . 15.6 16 miles __ .. _____ . _____ 48.0 20 miles ____________ 60. 9. 

25 miles -- -- -- ---- -- - 69.9 

30 miles _____________ . 75.9 

5.2 18.8 

16.0 58.0 

20.3 73.6 

23.3 84.5 

25.3 91.7 

-

-0.085 I o. 26o 1 

0. Wr-~2 

1 

0.379 

0.411 

The curve shown in fig. 6 is for a moderately loaded 12-foot mill 

(536.2 foot-pounds per stroke). It starts at a wind velocity of 11 

10 

70 

60 

50 

20 

10 ; 

VELOCITY OF WIND IN MILES PER HOUR. 

15 20 25 30 

0 0 

00 0 ....... fl"' ~ ~ 

v 8 --~ 

I ~ ~ 10 

r;~ 

I 

0 I 

I 

FIG. 6.-Diagram showing results with mill No. 2-12-foot Woodmanse Mogul. 
U. S. GEOLOGIC.6.L SURVEY WATER -SU PP LY PAPE:::R NO. 41 PL. Ill 

V I EW OF MILL NO.2 {12-FOOT WOODMANSE MOGUL ) AND ANEMOMETER. 
~fiTRPHY.) PUMPING l\ULLS TESTED. 29 

miles an hour. It ascends very rapidly, reaching a maximum at 18 

miles an hour, and giving 60 strokes to the mile. The rest of the 

curve to 30 miles has a gentle slope. The number of strokes per 

minute increases from about 5 at 12 miles to about 25 at 30 miles an 

hour, and will continue 

to increase to probably 

28 a minute in a 40-mile 

wind. 

Mill No. 3.-This is a 

12-foot Aermotor manufactured by the Am·motor 

Company, of Chicago, 

Illinois. Pl. IV shows 

the mill with its tower, 

pump, and pond. and fig. 

7 shows its working 

parts. This mill had been 

in use about one year at 

the time of test, and all 

of the parts were in good 

working order. The 

tower is of wood, the axis 

of the wheel being 30 feet 

above the ground. The 

exposure is very good. 

The wheel has 18 curved 

~ails, each 44 by 18! by 7! 

inches, set at an angle of 

31 o to the plane of the 

wheel. It is back-geared, 

3t to 1, and is held in the 

wind by a spring. The 

pump is of the Stone type, 

shown in figs. 8 and 9; 

the check valve is of the 

single-flap variety, the 

plunger valve of the 

double-flap variety. The FIG. 7.-Working parts of Aermotor 

cylinder is 9t inches in 

diameter, the supply pipe 4 inches in diameter, and the discharge 

pipe 10 inches in outside diameter; the length of stroke is 12 inches 

and the discharge per stroke 14t quarts. The well is 4 feet by 4 

feet to a depth of 8 feet-nearly down to water. From that point 

to a depth of 18 feet it is 3 feet in diameter; and from there 

three pipes, 12 inches in diameter, extend down 5 feet farther. The 

lift at the time of test was 13! feet, the barometric pressure 27.2 

inches, and the temperature 85° F. The water is pumped into a pond 
30 THE WINDMILL. [N0.4J, 

80 feet by 75 feet, and a depth of 22 inches can be drawn off. The 

cost of the plant, including mill, tower, pump, and pond, was $145. 

The greatest number of strokes per minute is probably 27 or 28 in a 

40-mile wind. In general appearance this curve is 

seen to resemble that of mill No. 2, but it is about 

4 miles farther to the left, due to lighter load. 

The results of the tests are as follows: 

Results of tests of mill No. S-12-foot Aermotor. 

[Load per stroke, 41.5.3 foot-pounds.] 

Revolu· 

Wind Strokes of Gallons Useful velocity per tions of 

hour. wind wheel pump pumped per horse · 

per minute. per minute. minute. powe1•. 

8 miles . _ .. __ 17.7 5.3 19.3 0.067 

12 miles. 40.0 12.0 43.5 0.151 16 miles . _____ 54.7 16.4 59.5 0.207 

20 miles . ___ , . 66.0 19.8 7L8 

i!lU 25 miles .. 7.7.0 28.1 83.6 1 

30 miles. ____ _ 83.3 ' 25. 0 . 90.6 5 

The curve shown in fig. 10 is for a rather 

lightly loaded mill (415.3 foot-pounds per stroke). 

It starts at a velocity of 6 to 7 miles an hour, 

ascends less rapidly than the one shown in fig. G, 

attains a maximum at about 15 miles an hour, 

when the number of strokes per mile is 62, and 

then descends slowly, reaching 50 strokes at 30 

miles. The number of strokes per minute increases 

from about 5 at 8 miles to 25 at 30 miles. 

Mill No . .¥.-This mill, shown in the fpreground 

of Pl. V, is an 8-foot Ideal windmill manufactured 

by the Stover .Manufacturing Company, . of l!'reeFw. s.-Stoue pump. port, Illinois. It had been in use about one year, 

and all of the parts were in good condition. The 

tower is of wood, the axis of the wheel being 48 feet above the gr·ound. 

The wheel has 15 sails, each 16~ by 7 by 30 inches, set at au angle 

of 29° with the plane of the wheel. It is back-geared, 2t to 1, and is 

held in the wind by a spring. The pump is of the Stone make. The 

diameter of the discharge pipe is 5i inches, of the supply pipe 3 inches. 

The length of stroke is 8 inches. The plunger and check valves are 

of the single-flap variety. The well is 2! feet by 2! feet down nearly 

to water- a depth of 5t feet. The 3-inch supply pipe extends down 

to a depth of 14 feet, and on the end of it is a 3-inch well point 6 feet 

long. The lift may vary from Sf to 20 feet. It was probably about 

12 feet at the time of tests. T'he discharge per stroke was 2 quarts. 

The mean barometric pressure was 27.19 inches, the mean tempera-
U. S. GE(){.OGICAL SURVEY WATER-SUPPLY PAPER NO. 41 PL. IV 

VIEW OF MILL NO. 3-12-FOOT AERMOTOR. 
MURPHY.] PUMPING MILLS TES'I'F.D. 31 

tnre 83° F. The water is pumped into a pond 115 feet by 31 feet and 

3 feet deep. The cost of the p lant, including mill, pump, well, and 

pond , was $80. The results of the tests are as follows: 

Res·ults of tests of mill No. 4- 8-foot Ideal. 

[Load per stroke, 50 foot-pounds.] 

I W ind velocity per hour. Revolution~ Strokes of Gallons U sefu I horse- of wind wheel pump per pumped per power . per minute. minute. minute. 

I 

12 miles. __ . __ ___ _____ 25.5 10.2 5.1 0.015 

16 miles .. . ~-- --- -- - · 48.2 19.3 9.6 0.029 I 20 mil es _____ ___ ______ 63.2 25.3 12.6 0.038 

25 miles .... ------- --- 70.3 28.1 14.1 0.043 

30 miles . __ --- - ------ 62.5 25.0 12.5 I 

0.038 

FIG. 9.- Details of Stone pump: a, Lower v"lvo seat; b, rin g guide t o lower valve; c, lower or· 

check valve; d , hook for removing lower valve; e, plunger and valve; f is a, b, and c co ~· 

bined. 

The curve shown in fig. 11, although for a rather lightly loaded 

mill-50 foot-pounds per stroke-shows that the mill starts in a 10-

mil e to an 11-mile winct. The maximum is reached at 19 miles, with 

a speed of 78 strokes. The right side of the curve is quite steep, a 

characteristic of this make of mill. Mill No. 18 is the same size and 

make as this mill, and yet with a load of 89.2 foot-pou nds it starts. in 

a 7-mile to an 8-mile wind, reaching a ru~xim.um at about 13 miles at 
82 THE WIND:M.ILL. (No.41. 

VELOCITY OF WIND IN MILliiS PEl!. HOUR. 

10 0 

0 

60 

0 0 0 0 0 0 '.,... 0 

/0 0 ~ 

I ---- 0 ---

I . I 

. 

1 0 I 

-- FIG. 10.-Diagram showing results with mill No. 3--:12-foot ,Aermotor. 

VELOCITY OF WIND IN MILES PER BOUH. 

10 15 oro 20 ' 80 00 0 

/ ~ o-..... 0 

7 0 ~ o'l. / "" 0 

~ v 

50 

/o 

1 ~ 

A.tl 

0 

~ 

- 0 

Q 

1iJ 

;FIG. 11.-Diagr&m 11howing results with mill No. 4-8-foot Ideal. 
U. S. GEOLOGICAL SURVEY WATER -SUPPLY PAPER NO. 41 PL. 1/ 

VI EW OF M I LLS NO. 4 (B-FOOT I DEAL ) AND NO.5 (B- FOOT AERM OTOR). 
MURPHY.] PUMPING MILLS TESTED. 33 

a speed of 104 strokes per mile. A second test, when the spring that 

holds the wind wheel in the wind was tightened somewhat, gave t.he 

maximum at a velocity of about 15 miles, with a pump speed of about 

114 strokes. The difference appeared to be due t,o the difference in 

pumps and wells. The rapid fall in the curve to the right of the highest point is due to the easy governing of the mill. 

Mill No. 5.-This mill, shown in the baekground of Pl. V, is an 

8-foot Aermotor manufactured by the Aermotor Company, of Chicago, 

Illinois. The tower is of wood, and is 28.5 feet high to the axis of wheel. 

The exposure is good, and all of the parts were in good working order 

at the time of tests, the plant having been in use about one year. The 

wheel has 18 curved sails, each 30 by 12-t by 5! inches, ·making an 

angle of 29! 0 with the plane of the wheel. It is back-geared, 3-~ to 1. 

The pump is of the Stone make. The discharge pipe is 6 inches in 

diameter, the supply pipe 3 inches in diameter .. The valves (check 

and plunger) are of the single-flap variety. The length of stroke is 

8 inches. The well is 4 feet by 4 feet to water, a depth of 10.5 feet. 

A 12-inch wooden curb extends 12 feet farther into the sand and 

gravel. 'fhe discharge per stroke was 3t quarts, and the lift 13 feet. 

The cost of plant, including pond, was $80. 

VELOCITY OF WIND IN MILES PER HOUR. 

10 15 20 25 

100 -- 0 

~0 

00 

, ~ - 0 ~ ~ 01 ~~ 

80 0 

~ ~ 

I 

I I 

f 

I i 

I 

! 

50 

40 I 

I 

30 

Pm.l2.-Diagram showing results with mill No. 5-8-foot Aermotor. 

IRR 41-01--3 
34 THE WINDMILL. (N0.41. 

The reflmlts of the tests of mill No. 5 are as follows: 

Results of tests of mill No. 5-8-foot Aerrnotor. 

[Load per stroke, 94.9 foot-pounds.] 

I Wind vel~lty per hour. 

Revolutions Strokes of I Gallon' Useful horse- of wind wheel pump per pumped per 

per minute. minute. minute. power. 

I 

12 miles __ .. ____ . 62.0 18.6 16.3 0.053 16 miles ______________ 83.7 25.1 22.0 0.072 

20 miles . _ . _ _ _ _ .. _. __ 99.3 29.8 26.1 

~~J 25 miles . _ ... _ .. _ .. _ .. 115.3 34.6 30.3 9 

30 miles . ___ . ___ .. _ ... 128.3 38.5 33.7 1 

This 8-foot mill, with a load of 95. foot-pounds, is seen to start in 

an 8-mile to a 9-mile wind (fig. 12), reaching a maximum at 13 to 15 

miles, with 95 strokes per mile. At 30 miles an hour it is making 77 

strokes per mile, or 39 strokes per minute. 'rhis curve indicates a 

rather heavily loaded mill. 

Mill No. 6.-rrhis mill, shown in the background of Pl. IV, is an 

8-footGem, manufactured by the United States Wind Engine and Pump 

Company, of Kansas City, Missouri. The working parts of the mill 

are shown in Pl. VI. The exposure was good and all of the parts were 

in good working order, the mill having been in use only about one 

year at the time of tests. The wheel has 24 curved sails, each 30t by 

10 by 4i inches, set at an angle of 35° with the plane of the wheel. It 

is back-geared, 3 to l. rrhe wheel is held in the wind by means of a 

weight. The pump is of the Stone make. The discharge pipe is 6 

inches in diameter, the supply pipe 4 inches in diameter. The length 

of stroke is 8 inches. The well is open to the water-a depth of 6i 

feet. The supply pipe is on a well point, the end of which is 16 feet 

below the surface of the ground. The lift was 9T\- feet and the discharge per stroke 3. 9 quarts. The tower is of wood, and is 24 feet 

high to the axis of the wheel. The mean barometric pressure was 27.02 

inches, the mean temperature 85° F. rrhe plunger valve is of the 

double-flap variety, and the check valve of the single-flap variety. 

The results of the tests are as follows: 

Results of tests of rnUl No. B-8-foot Gern. 

[Load per stroke, 77.6 foot-pounds.] 

I Revolutions Strokes of Gallons I U f 1 I Wind Vel~lty per hour. of wind wheel pump per pumped per se u ho 

per minute. minute. minute power. . I 

I 

I 12 miles .. ____________ 37.2 12.4 12.1 0.02 I 

I 16 miles .. ____________ 53.7 17.9 17. ,) 0.04 I 20 miles .. _ . __ . ________ 66.0 22.0 21.5 0.05 

I 25 miles ___ . _ .. __ .. __ . 76.2 25.4 

I 

24.7 

I 

0.05 

I 

30 miles .. _____ . . _ . __ . 85.5 28.5 27.8 0.06 

9 

2 

1 

9 

~ 
MURPHY.] PUMPING MILLS TESTED • 35 

• 

Comparing the number of strokes per minute of mills Nos. 4, 5, and 

6, it is seen that although No. 5 is carrying a much heavier load. than 

either of the other mills, it makes more strokes and does much more 

work at all velocities. 

Mill No. 7.-This is a 12-foot Aermotor similar to mill No.3. The 

tower is of steel, having a height of 31 feet to the axis of the wheel. 

The exposure was good and all of the parts were in good working order, 

the plant having been in use less than one year when tests were made. 

The pump is of the Stone make and is like that of mill No. 3, except 

that the check valve is of the solid-lift variety. The lift was 15f feet 

and the discharge 14.3 quarts per stroke. The water is pumped into 

a pond 1'35 feet by 50 feet by 2f feet. 

Comparing the results of the tests of this mill with those of mill 

No. 3, it is seen that the latter is somewhat more heavily loaded than 

the former and makes a few less strokes per minute, but that its 

horsepower is a little greater. The effeet of the larger load is shown. 

The results of the ·tests of mill No. 7 are as follows: 

Results of tests of mill No. 7-12-foot Aermotor. 

[Load per stroke, 461.9 foot-pounds.] 

I Wind vel~ity per hour. 

Revolutions Strokes of Gallons Useful horse- of wind wheel pump per pumped per 

per minute. minute. minute. power. 

12 miles_ .. ___ . _______ 38.0 11.4 40.7 0.160 16 miles. __ : ______ . ___ 52.7 15.8 '56.5 0.221 20 miles. ____ . ___ . ___ . 63.3 19.0 67.9 0.266 25 miles . __ . _____ . ____ 73.7 22.1 79.0 0.309 30 miles. _______ . _____ 78.3 23.5 84.0 0.329 

Mill No. 8.-This is a 10-foot Star wooden mill, manufactured by 

Bradley, Wheeler & Company, of Kansas City, Missouri. The tower 

is of wood, and the axis of the wheel 35f feet above the ground. The 

water is pumped into an elevated tank 20 feet above the surface of 

the ground and is used for irrigation. The wheel has 60 plane sails, 

each 37 by 5 by 2-! inches, set at an angle of 33° to the plane of the 

wheel. It is held in the wind by means of a weight. It is not backgeared, a stroke of the pump being made to each revolution of the 

wheel. The supply pipe is 2 inches in diameter and terminates in a 

well point, the end of which is 18 feet below the surface of the ground. 

The discharge pipe is ll- inches in diameter. The cylinder is 3 inches 

in diameter, the length of stroke 5 inches. 'The lift may vary between 

28f and 37 feet. It was estimated to be about 30 feet at the time of 

measurement. The discharge per stroke was 0.24 quart. The cylinder leaked some at the time of tests. After a new cylinder was put 

in the discharge per stroke was increased to 0.40 quart. The mean 
36 THE WINDMILL. (NO, 41. 

barometric pressure was 27.04 inches, the mean temperature 78° F. 

The results of the tests are as follows: 

I 

Results of tests of mill No. 8-10-foot Star wooden mUZ. 

[Load per stroke, 15 foot-pounds.] 

Revolutions i Strokes of i Gallons 

Wind Useful horse-' velocity per hour. of wind wheel pump per pumped per 

per minute. minute . minute. power. 

L2 . 8 miles . ___________ .. 28.0 28.0 1.7 0.013 miles _ _ _ _ _ _ _ _ ____ . 30.0 30.0 I 1.8 0.01~ I 

'rhese res~lts show the effect of the very light load and the readiness with which the wind wheel turns out of the wind. It makes 28 

strokes per minute in an S-mile wind and less than that in a 16-mile 

or higher wind. 

Mill No. 9.-This is a 16-foot Aermotor. The tower is of steel, and 

the axis of the wheel is 30 feet above the ground. The wheel has 18 

VELOCITY OF WIND IN MJI,ES PER HOUR. 

10 15 20 30 

60 0 --

00 

e 0 0 0 0 

0~ ~s 0 0 0 

-r--._ 0 

/ 

o/ 

0 

0 ~ 

0 ~ ~ 

50 

If I 

10 

FIG. 13.-Diagram showing results with mill No. 9-16-foot Aermotor. 

curved sails, each 59 by 25! by lOt inches, set at an angle of 30° with 

the plane of the wheel. It is back-geared, 3 to 1. The discharge 

pipe is 12 inches in diameter, the supply pipe 6 inches in diameter, 

the cylinder 8 inches in diameter. The stroke is 16 inches. The well 

is 4 feet by 6 feet to a depth of 23 feet, 2 feet by 2 feet for the next 8 

feet, and 18 inches in diameter for the next 14 feet. The water was 39t 

feet below the surface of the ground. The lift was 44:1- feet and the 
MURPHY.) PUMPING MILLS TESTED. 37 

discharge per stroke 11 quarts. The check valve is of the single-flap 

variety and the plunger valve of the double-flap variety. The mean 

barometric pressure was 27.04 inches, and the mean temperature 93° 

F. This plant had been in use about three years. The results of the 

tests are as follows: 

Results of tests of mill No. 9-16-foot Aermotor. 

[Load per stroke, 1,013 foot-pounds .. ] 

I Wind vel~Jty per hour. 

Revolutions I Strokes of Gallons 

of wind wheel pump per pumped per 

per minute. minute. minute. 

12 miles_. ____ .. __ . ____ 31.8 10.6 29.1 

16 miles __________ ·-- 42.3 14.1 38.8 

Useful horsepower. • 

0.325 

0.433 I : 

I 

20 miles_ . ___ . __ . _____ 51.6 17.2 47.3 25 miles ______ . _ . ____ . 0. 548 j 58.8 19.6 53.9 0.601 30 miles ___ . _ . ________ 63.0 21.0 57.7 0.644 

I --~~-

The curve shown in fig. 13 starts at a wind velocity of 8 to 9 miles, 

and reaches a maximum at 13 miles, with a speed of 53 strokes per 

mile. From that point to a velocity of about 19 miles the curve is 

nearly horizontal; after 19 miles it descends slowly to 32 miles, with 

38 strokes per mile. The speed increases from 11 strokes per minute 

at 12 miles to 21 strokes per minute at 30 miles an hour. 

Mill1Vo. 10.-This is an 8-foot Ideal. The tower is 'of wood, the 

axis of the wheel being 30 feet above the ground. The wheel has 15 

curved sails, each 31 by 19 by 7 inches, set at an angle of 29f0 with 

the plane of the wheel. It is back-geared, 2f to 1. The supply pipe 

is 1f inches in diameter, the cylinder 2t inches in diameter. The 

pump is a eommon hand pump, with lift valve of the flap form and 

plunger of the lift variety. The valves leak some, as the discharge is 

greater when the pump is working rapidly than when it is working 

slowly. The supply pipe is on a well point 2 feet long and 1f inches 

in diameter, the lower end of which is. 50 feet below the surface of the 

ground. The lift was 33 feet and the discharge per stroke one-third 

of a quart when pumping quite rapidly. 'fhe mean barometric pressure was 26.94 inches, the mean temperature 97° F. The results of the 

tests are as follows: 

Results of tests of mill No. 10-8-foot Ideal. 

[Load per stroke, 22.8 foot-pounds.] 

velocity per lwur. of wind wheel pump per pumped per Useful horse- F \ Revolutions Strokes of Gallons 

per minute. minute. minute. power. 

I 

j 8 miles ____ . ___ .. _ ... __ 12 miles _________ ~ .. .. les _______ - _ .. - -

35.2 

62.5 

83.2 

14.1 

25.0 

33.3 

-1.2 

2.1 

2.8 les . ________ . _ _ _ _ _ _ .. _______ .. ____________________ .. __ 

0.010 

0.017 

0.023 

0.032 
38 THE WINDMILL. (N0. 41. 

Mill No. 11.-This ~s a 12-foot Ideal, the working parts of which 

are shown in fig. 14. The tower is of steel, the axis of the wheel 

being 30 feet above the ground. The exposure was good, and all of the 

FIG. 14.-Working parts of mill No. 11-12-foot l<'le11l, 

parts were in good working order when mill was tested. The wheel 

has 21 curved sails, each 31 by 19 by 7 inches, set at an angle of 29t0 

to the plane of the wheel. It is back-geared, 2f to 1, and the wheel 
MURPHY.) PUMPING MILLS TESTED. 39 

is held in the wind by a spring. The discharge pipe is 8 inches in 

diameter, and the length of stroke is 12 inches. The supply pipe 

consists of two 3-inch pipes 14 feet long, each terminating in a 3-inch 

well point 3 feet long. The valves (check and plunger) are of the 

single-flap variety. The water was 39 feet below the surface of the 

ground. The lift, as nearly as could be ascertained at the time of 

measurement, was 45 feet, the discharge per stroke 9 quarts. The 

water is pumped into a pond 60 feet by 40 feet by 6 feet. This plant 

had been in use about three years. The mean barometric pressure 

was 26.91 inches, the mean temperature 91 o F. The results of the 

tests are as follows: 

Results of tests of mill No. 11-12-foot Ideal. 

[Load per stroke, 843.7 foot-pounds.] 

Revolutions Strokes of Gallons 

Wind Useful horse- velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. power. 

12 miles. __ . __ ._ ... ___ 12.0 4.8 10.8 0.123 16 miles. __ . ___ . ______ 31.7 12.7 28.6 0.325 20 miles. _____________ 47.0 18.8 42.3 

~ 25 miles .. _____________ 58.2 23.3 52.5 0 30 miles .. _____ . _______ 62.5 25.0 56.2 9 

Mills Nos. 9 and 11 pump water into the same pond from the same 

depth. It will be seen from these results that for wind velocities of 

VELOCITY OF WIND IN MILES PER HOUR. 

10 15 20 25 

60 •. ( 

i 0 

) ~0 0 0-

----- i ~ 

v c 

50 

I 

v 

i 

20 I 

10 " ~'IG.15.-Diagram showing results with mill No. 11-l:Hoot Ideal. 
40 [N0.41. 

20 miles or more the 12-foot mill is pumping nearly as much water as 

the 16-foot mill; for velocities of 1::? miles or less t,he 16-foot mill is 

FIG. 16.-Working parts of Frizell cylinder. 

pumping mueh more water than 

the 12-foot mill. 

This curve (fig. 15) is for a 

heavily loaded ( 843. 7 footpounds per stroke) 12-foot milL 

It starts with a velocity of about 

10 miles an hour, and reaches 

a maximum at about 23 miles, 

with a speed of 57 strokes per 

mile. At 30 miles it is making 

51 strokes per mile. The maximum point of this curve is much 

farther to the right than that of 

any other curve. The number 

of strokes increases from 5 per 

minute at 12 miles to 25 per 

minute at 30 miles. 

Mill No. 12.-This is a 14-foot 

Ideal, shown in Pl. VII. The 

tower is of steel and is 30 feet 

high to the axis of the wheel. 

The wheel has 24 curved sails, 

each 48-! by 17 t by 8 inches, set 

at an angle of 30° with the plane 

of the wheel. It is back-geare<l, 

2i to 1. The pump is of the 

Frizell make (shown in fig. 16). 

The discharge pipe is 10 inches 

in diameter, the cylinder 9-! 

inches in diameter, the supply 

pipe 6 inches in diameter, terminating in a well point 10 feet 

long and 6 inches in diameter, 

the lower end of which is 32 feet 

below the surface of the ground. 

The lift, as nearly as could be 

estimated, was 11 feet, the discharge per stroke 11. 6 quarts. 

The mean barometric pressure 

was 27.04 inches, the mean tern~ 

perature 81 o F. The water is 

pumped into a reservoir 100 feet 

by 100 feet by 3 feet deep. The pump had been in use about one 

year. The results of ·the tests are as follows: 
U. $. GEOLOGICAL SURVEY WATER·SUPPLV PAPER NO. 41 PL. VI 

WORKING PARTS OF MILL NO. 6- 8- FOOT GEM . 
'MURPHY.] PUMPING MILLS TESTED. 41 

Results of tests of rnill No. 12-14-foot Ideal. 

[Load per stroke, 26.3.5 foot-pounds.] 

I Wind velocity per hour. 

Revolutions Strokes of Gallons Useful horse- of wind wheel pump per pumped per 

per minute. minute. mmute. power. 

I 

8 miles ___________ . _ 7.7 3.1 8.9 0.025 12 miles ______ . __ : ___ 27.2 10.9 30.1 0.087 16 miles ________ .. ____ 39.3 15.7 45.1 0.125 20 miles ___ . _______ .. 48.0 

I 

19.2 55.2 0.153 25 miles _________ ... __ 53.7 21.5 61.8 0.173 I 

This curve (fig. 17) is for a very lightly loaded (263.5 foot-pounds)· 

14-foot mill. This load is only 31 per cent of that of the 12-foot mill, 

No. 11. The curve starts in a 7-:niile to au S-mile wind, and reach~s 

a maximum at 15 miles, with a speed of 58 strokes per mile of wind. 

At 30 miles the speed is 47 strokes. Although this is a very lightly 

VELOCITY OF WIND IN MILES PER HOUR. 

10 15 25 ". - Oll 

0 ~ ---- ~ 0 

~ ~ ......... 00 v ~ 

40 I 

30 J 

2( I 

I 

10 . I 

FIG. 17.-Diagram showing results with mill No. 12-14-foot Ideal. 

loaded mill it does not make many strokes per minute. In fact, 

although it is not as heavily loaded as the 12-foot mill, No.3, it does 

not make as many strokes per minute as the latter mill, and it is producing much less power than mill No. 3. 

Mill No. 13.-This is a 12-foot Aermotor (shown in Pl. VIII). The 

tower is of wood, with the axis of the wheel 25 feet above the ground. 

The exposure was good and the plant in excellent condition, having 
42 THE WINDMILL. {No.41. 

been in use about one year at the t.ime of tests. The wheel is the same 

as t,hat of No. 3. ~rhe pump is of the Stone make. The discharge pipe 

is 10 inches in diameter, the supply pipe 5 inches in diameter, on a 

well point 10 feet long, the lower end of which is 17 feet below the 

surface of the ground. The length of stroke is 12 inches. The 

plunger valve is of the double-flap type, and the check valve of the 

single-flap type. The discharge per stroke at the time of test was 

14.4 quarts and the lift about 11 feet. The mean barometric pressure was 27.09 inches, the mean temperature 91 oF. The results of 

the tests are as follows: 

Results of tests of mill No. 13-12-foot Aermotor. 

[Load per stroke, 330 foot-pounds.] 

F Revolutions Strokes of Gallons 

Wind Useful horse- velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. power. 

-------- 12 miles .. _ . _. __ . __ 36.7 11.0 39.6 - 0.110 

i 

16 miles. _________ ._. _ 57.0 17.1 61.6 0.171 20 miles _________ 70.0 21.0 75.6 0.210 

25 miles . __ . ______ .. ___ 82.0 24.6 88.6 0.247 30 miles __ .. ________ .. 91.7 27.5 99.0 0.275 

i 

The important difference between this plant and No. 3 is that the 

latter has a 4-inch supply pipe and an open well, while the former has 

l 5-inch supply pipe on a well point. The useful load per stroke of 

mill No. 13 is 20 per cent less than that of mill No. 3, and the number of strokes per minute of No. 13 is slightly greater_ than that of 

No. 3. It appears that the well point offers some resistance, but how 

much can not be said from t,his data. 

Mill No. 14.-This is a 12-foot Gem, like the one shown in Pl. IX, on 

a 60-foot steel tower. 11he pump is of the Gause make. 'rhe cylinder 

is 8 inches in diameter, the length of stroke 9 inches. The supply is 

from a 12-inch pipe in an open well. The discharge per stroke was 

9! quarts and the lift 15f feet. The wind velocity was not measured. 

Mill No. 15.-This is a 10-foot Gem similar to that shown in Pl. IX. 

The tower is of wood, the axis of the wheel being 34 feet above the 

ground. The mill was in good working order, but the exposure was 

not good, on account of trees. The wheel has 24 sails, each 36 by 11 

by 4! inches, set at an angle of 35° with the plane of the wheel. 

It is baek-geared, 3 to 1. The pump is of the Stone make. The discharge pipe is 8 inches in diameter. The supply pipe is on a 3-inch 

well point 8 feet long, the lower end of which is 21 t feet below the surface of the ground. The plunger valve is of the single-flap form. 

Depth to water is 10 feet. The discharge per stroke was 7 quarts, the 

lift about 15 feet. The mean barometric pressure was 27.05 inches, 

the mean temperature 84:° F. 
U. S. GEOLOGICAL SUAV!OY WATER-SUPPLY PAPIOR NO. 41 PL. VII 

VIEW OF MILL NO. 12-14-FOOT IDEAL 
U. 8. GEOU)GICAL. SURVEY WAfER-SUPPLY PAPER NO. 41 PL. viii 

VIEW OF MILL NO. 13-12-FOOT AERMOTOR. 
MURP't!Y.] PUMPING :MILJ~S TESTED. 

The results of the tests are as follows: 

Results of tests of mill No. 15-10-foot Gern. 

[Load per stroke, 219 foot-pounds.] 

I Wind velocity per hour. 

Revolutions Strokes of Gallons 

of wind wheel pump per pumped per 

per minute. minute. mmute. 

I 

12 miles ___ . __________ 23.4 7.8 13.6 16 miles ______________ 35.7 11.9 21.0 20 miles _______ . ______ 44.1 14.7 25.7 25 miles ______________ 43.8 14.6 25.5 

43 

Useful horsepower. 

0.053 

0.082 

0.101 

0.099 

This mill revolves very slowly, indicating a heavy load. Its useful 

horsepower, however, is little greater than that of mill No. 5. 

Mill No. 16.-This is a 10-foot Halliday, pumping water into the 

same pond as No. 15. It is similar to the mill shown in fig. 20. The 

tower is of wood, the axis of the wheel being 28 feet above the ground. 

The wheel has 78 sails, each 36t by 4 by 2-!- inches, set at an angle 

of 35.5° to the plane of the wheel. It is not back-geared. The 

pump is of the Gause make, with a discharge pipe 6 inches in diameter and a supply pipe 4 inches in diameter. There is a 6-inch galvanized-iron pipe, forming an open well, extending 15 feet into the water. 

The depth to water was 11 feet, the lift 16 feet, and the discharge per 

stroke 3 quarts. The mean barometeric pressure was 27.02 inches, 

the mean temperature 94° F. The results of tests are as follows: 

Results of tests of mill No. 16-10-foot wooden Halliday. 

[Load per stroke, 100 foot-pounds.] 

Revolutions Strokes of Gallons 

Wind Useful horse- velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. power. 

I 

8 miles ______________ 4.0 4.0 3.0 0.012 

12 miles ______________ 22.6 22.6 16.9 0.067 16 miles. ___ '" _________ 33.9 33.9 25.4 _Z!j 20 miles ______________ 42.7 42.7 32.0 0 25 miles ________ . ____ . 52.5 52.5 39.3 9 

This 10-foot wooden mill is seen to be doing more useful work than 

the 10-foot steel Gem, No. 15. Usually, however, the direct-stroke 

wooden mills do less work than the back-geared steel mills of the same 

size. 

Mill No. 17.-This is a 12-foot improved Gem on a 30-foot steel 

tower. The wheel has 32 curved sails, each 42 by 11t by 4! inches, 

set at an angle of 37° with the plane of the wheel. It is back-geared, 

2 to 1. The pump is of the Gause type, with an 8-inch discharge pipe, 

a 4-inch supply pipe, 12 inches stroke, and an open well formed of a 

12-iuch wooden casing. The depth to water was 17-!- feet, and the 
44 THE WINDMILL. [No. 41. 

discharge per stroke 8-! quarts. The mean barometrie pressure wa8 

27.05 inches, the mean temperature 93° F. The results of the tests 

are as follows: 

Results of tests of mill No. 17-12-foot improved Gem. 

[Load per stroke, 385 foot-pounds.] 

I Wind velocity I~r hom. 

Revolutions Strokes of Gallons Useful horse- of wind wheel pump per pumped per 

per minute. minute. minute. power. 

I 12 miles ________ . ___ . 12.0 6.0 12.7 0.070 

I 16 miles. ___________ ... 25.6 12.8 27.2 0.149 

I 20 miles ___________ ._. 34.6 17.3 36.8 0.202 

!L____ 

j 

This mill, although nearly new, does not work well. It is out of 

plumb. Only a few measurements of the number of strokes per mile 

of wind were made. 

Mill No. 18.-This is an 8-foot. Ideal on a 36-foot wooden tower. 

The exposure was good and the parts in good working order. The 

wheel is like that of mill No. 4. The pump is of the Stone make, with 

a 6-inch discharge pipe. There is no supply pipe, the cylinder being 

under water, with a inches opening to it from below. The check valve 

is of the lift variety, the plunger valve of the single-flap variety. The 

well is dug to a depth of 8 feet. It is 4-i feet in diameter. In the 

bottom a 10-inch galvanized-iron pipe extends down several feet. It 

was 11 feet to water. The lift was 14-i feet and the discharge per 

stroke 2.92 quarts. The mean barometric pressure was 27.01 inches, 

the mean temperature 83° F. 'rhe cost of the plant, including pond, 

was $125. The results of the tests are as follows: 

I 

Results of tests of rnill No. 18-8-foot Ideal. 

[Load per stroke, 89.2 foot-pounds.] 

Revolutions Strokes of Gallons 

Wind velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. 

8 miles _______ ._._ ... 20.0 8.0 5.8 

12 miles ___ . __ . __ .... _. 50.5 20.2 14.6 

16 miles .. _____ . ___ . _. 65.2 26.1 18.9 

20 miles ... __ . ___ . _ . _ . 70.0 28.0 20.3 25 miles ___ . ___ . _____ . 68.7 27.5 19.9 

Useful horsepower. 

0.022 

0.054 

!!J 6 

4 

After the spring which holds the wind wheel of this mill in the wind 

was tightened, the number of strokes per mile of wind was increased 

from 98 to 114 in a 16-mile wind, from 84 to 102 in a 20-mile wind, and 

from 66 to 79 in a 25-mile wind. 

Mill No. 19.-This is a 12-foot Gem (shown in Pl. IX) on a 30-foot 

wooden tower. The exposure was good and the mill in good working order. The wheel is like that of mill No. 17. The pump is of 

the Stone make, with a 10-inch discharge pipe and a 4-inch supply 
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER NO. 4 1 PL. IX 

VI EW OF MILL NO, 19- 12 -FOOT G EM . 
MURPHY.) PUMPING MILLS TESTED. 45 

pipe. The length of the stroke is 10 inches. The supply pipe is on a 

4-inch well point 9 feet long, the end of which is 23 feet below the 

surface of the ground. The check valve is of the lift type and the 

plunger valve of the single-flap type. The lift was about 18 feet and 

the discharge per stroke 12 quart,s. The mean barometric pressure 

was 27.13 inches, the mean temperature 70°F. The water is pumped 

into a reservoir 120 feet by 60 feet. The results of the tests are as 

follows: 

Results of tests of n~ill No. 19-12-foot Gem. 

[Load per stroke, 450 foot-pounds.] 

elocity per hour. I Willdv 

~---;2 mi les __ .. ____ . _____ les ____________ . _ 

: 

16mi 

20mi 

25 mil 

les _ _ _ _ _ _ . __ - ..... 

es ---------·----

Revolutions 

of wind whee1 

per minute. 

12.4 

23.8 

29.4 

32.0 

Stroke of Gallons 

pump per 

minute. 

pumped per 

minute. 

6.2 18.6 

11.9 

I 

35.7 

14.7 44.1 

16.0 48.0 

i 

Useful horsepower. 

-

0.085 I I 

0.162 

0.201 

0.219 

~-

This curve (fig. 18) shows that a 9-mile wind is necessary to start 

this mill, and that the greatest number of strokes per mile of wind 

VELOCITY OF WIND IN MILES PER HOUR. 

10 V> 20 

60 

50 

0 0 0 

- f,.oe'""' 0 

/' 0 

0 --. ~ f....a. -

v --. 1----

/ 

10 

v 

I 

20 

I 

FIG. 18.-Diagram showing results with mill No. 19-12-foot Gem. 

is 45-about 25 percent less than most 12-foot steel back-geared mills, 

being at the rate of 6 strokes at 12 miles and 16 strokes at 25 miles an 

hour. ~.rhe load of this mill is somewhat greater than that of No. 3, 

and its power should be equal or greater, but it is seen to be much less. 
46 THE WINDMILL. [No.41. 

Mill No. 20.--This is a 15-!-foot Jumbo (shown in Pl. X, A). Its 

axis is a steel shaft 8 feet above the ground. It has 6 sails, each 9f by 

3-! feet, with an outer radius of 7! feet and an inner radius of 4-! feet. 

This mill operates two pumps, one at each end of the axis, each pump 

having a 6-inch cylinder, a 3-inch discharge pipe, and a 3-inch supply 

pipe on a well point 5 feet long. 1,be discharge per stroke of the 

two pumps was 10 quarts, the lift about 14 feet. The mean barometric pressure was 27.09 inches, the mean temperature 85° F. The 

anemometer was held 14 feet above the surface of the ground, or 

at the elevation of the center of a sail when in its highest position. 

The wheel is set in a large box the top of which is on a level with the 

axis of the wheel, to prevent the wind from striking the part of the 

wheel below its axis. The results of the tests are as follows: 

Results of tests. of mill No. 20-15t-foot Jurribo. 

[Load per stroke, 291.2 foot-pounds.] 

I Revolutions Strokes of Gallon• IU f 1 h I Wind velocity per hour. of wind wheel pump per pumped per se u orseper minute. minute. minute. power. 

16 miles .. __ . _ . __ . ___ . 5.3 5.3 13.2 0.047 LO miles-----·.····---· 10.7 10.7 26.7 0.09~ 

The curve shown in fig. 19 is seen to be different from the others in 

that it apparently has no maximum. It starts at a wind velocity of 13 

10 

50 

40 " 

I, 

10 

I 

VELOCITY OF WIND IN MILES PER HOUR. 

15 20 25 30 

' r 

...,. 

~/ v 

0~ 

Vo 

0 

0 Voo 

j 0 

10 

I 

FIG. 19.-Diagram showing results with mill No. 20-l[)t-foot Jumbo. 

to 14 miles, and beyond 20 miles it appears to be a nearly straight 

line. Comparing these results with those of No. · 5, it will be seen 

that this mill is inferior in power to a good 8-foot steel mill. 
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER NO. 4 1 PL. X 

.A. VI EW O F M I L L NO. 20-lSfr-FOOT JUMBO. 

R. VIEW OF DEFEND E R MILL AND PUMP KNOWN AS "WATER ELEVATOR." 
U. S. GEOLOGICAL SURVEY WATER -SUPPLY PAPER NO. 41 PL. XI 

· VI EW QF MI LL NO. 21-12-FOOT ALL ~AY. 
~!URPHY.] PUMPING MILLS TESTED. 47 

Mill No. 21.-This is a 12-foot Halliday (shown in Pl. XI) on a 31-

foot wooden tower. It was made by the 1]nited States Wind Engine 

and Pump Company, of Batavia, Illinois. The working parts are 

FIG. 20.-Working parts of Halliday mill: A, bed plate; A', fan arm; B, turntable; B', regulating rod; C, front plate; C', assisting weight; D, sliding head; E, tie rod; F, forked lever; ll", 

fans or sails; G', truss frame; H, truss rod; L, pitman; L ' , fan lever; M, crank plate; ~l-1' M', 

masts; P, weight lever; R, shut-off rod; R' , shut-off rod lever; S, main shaft; S', sleeve; V, vane; 

V', vane arm; W, weight; W ' , connterweight; X, swivel box; Y, spider; Z, sliding box. 

shown in fig. 20. The wheel has 64 sails, each 42t by 5 by 2i inches, 

set at an angle of 35-0 with the plane of the wheel. It is not backgeared, and regulates itself on the centrifugal principle-the sails 
48 THE WINDMILL. (NO. 41. 

taking the direction of the wind. The pump is of the Stone .make, 

with 7f -inch discharge pipe, 4-inch supply pipe, and 7 inches stroke. 

The check valve is of the lift variety, the plunger valve of the 

double-flap variety. '!'he well, which is open, is formed by a wooden 

curb, 12 inches in diameter, sunk i.n the bottom of a dug well 9 feet 

deep. The depth to water was 11 feet and the lift 11 feet. The discharge per stroke was 4t quarts when pumping quite rapidly (30 

strokes per minute). The valves were not in very good repair and 

the pump lost its priming after a time. The results of the tests are 

as follows: 

1 

1 

2 

' 2 L 

Result11 of test ~ of mill No. 21-12-foot wooden Halliday. 

[Load per stroke, 141.5 foot-pounds.] 

Revolutions Strokes of Gallons Useful hor:l ind velocity per hour. of wind wheel pump per pumped per per minute. minute. minute. power. 

2 miles ____ __________ 14.0 14.0 15. 9 0.060 6 miles _______ _______ 28.5 28.5 32.1 0. 121 0 miles ... _________ .. 37.3 37.3 42.0 0.159 5 miles .. ____ . __ _ ... _ 44.6 44.6 50.2 0.1~ 

This curve (shown in fig. 21), which is for a lightly loaded (141.5 

foot-pounds) direct--stroke 12-foot mill, will be seen to start at a wind 

VELOCITY 0~' WIND IN MILES PER HOUR. 

10 15 20 25 

120 0 , 

~ 

100 v. " 0 -

I 

n/ 

I ·f 1/ 

~ 

I 

I 

FIG. 21.-Diagram showing results with mill No. 21-12-foot Halliday. 

velocity of 9 to 10 miles and to reach a maximum at 19 miles, with a 

speed of 112 strokes per mile. At 30 miles the number of strokes is 
]I[URPHY.] PUMPING MILLS TESTED. 49" 

about 98 per mile. The number of strokes per minute varies from 14 

at 12 miles to 45 at 25 miles. The power of this mill is only about 

half that of the 12-foot Aermotor, No. 3. 

J.lfill No. 25.-This is an 8-foot steel mill on a 32-foot steel tower, 

made by Fairbanks, Morse & Company. The wheel has 18 curved sails, 

each 29 by 11! by 5-! inches, set at an angle of 29° with the plane 

of the wheel. It is back-geared, 2! to 1. The pump is of the common hand variety, with a 2!-inch cylinder, lf-inch supply and discharge pipes, and 4 inches stroke. The well is open, 6-! feet to water. 

The discharge per stroke was 0. 31 quart and the lift St feet. The 

water raised is used for watering stock. The results of the tests are 

as follows: 

Results of tests of mill No. 25-8-foot Fairbanks-Morse steel mill. 

[Load per stroke, 5.5 foot-pounds.] 

Revolutions Strokes of Gallons 

Wind Useful horse- velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. power. 

8 miles ______________ 30.7 12.3 1.0 0.002 12 miles ______________ 73.0 29.2 2.3 0.005 16 miles ______________ 93.2 37.3 2.9 

~ 20 miles_. ____________ 95.0 38.0 3.0 8 25 miles ______________ 83.2 33.3 2.6 5 

This is a very lightly loaded mill-only 5.5 foot-pounds per stroke of 

pump. The number of strokes 

per minute in light winds is 

large; the number of strokes per 

minute in a 25-mile wind is only 

33. 3, compared with 38 in a 

20-mile wind. A comparison of 

this mill with No. 5 will show 

the difference between a small 

pumping outfit for stock purposes and one for irrigation. 

Mill No. 30.-This is a 16-foot 

Irrigator manufactured by M. 

Schow, of Kinsley, Kansas. It is 

a power mill, but not geared forward, and works a pump called a 

" water elevator." The tower is 

of wood, 22 feet to axis of wheel. 

The wind wheel has 10 plane 

wooden sails, each 70! by 16 by 

13! inches, set at an angle of 

39° to the direction of the wind. 

VELOCITY OF WIND IN MILES PER HOUR. 

10 15 20 

FIG. 22.-Diagram showiug revolutions of wind 

wheel of mill No. 30-16-foot Irrigator. AB is 

for a load of 32 foot-pounds per revolution of 

wind wheel; CD is for a load of 251 foot-pounds; 

ED is for a useful pump load of 337 foot-pounds. 

The vertical shafting is geared back 30 to 13, and the horizontal shaft 

is geared forward 13 to 30. The water is lifted from a well 8 feet 

IRR 41-01--4 
50 THE WINDMILL. [No.41. 

by 10 feet (7 feet depth to water), cased with wood. The buckets 

of the elevator are made of galvanized iron and are 14 by 7t by 5t 

inches, set 18 inches center to center, and hold 3 gallons each. Each 

bucket has a valve in its bottom. The lift is about 11 feet, and there 

are 20 buckets on the elevator chains. There is a box in bhe bottom 

of the well into which the buckets dip to get their supply of water. 

This box has a screen in its bottom to keep out the sand. The mill 

does not govern well, on account of side draft. The mean barometric 

pressure was 27.7 inches, the mean temperature 72° F. The results 

of the tests are as follows: 

Results of tests of mill No. 30-16-foot Irrigator. 

DLood Numberofrevolutionsof wind wheel UMful ho.-sepower at given wind I per minute at given wind velocities velocities (per hour). 

per rev- (per hour). 

olution brake. of wind 

wheel. 8 12 15 20 25 8 12 15 

miles. miles. miles. miles. miles. miles. miles. miles. miles. miles. 

----------------------

20 I 25 

Pounds. Ft.-lbs. 

16 

2 

251 

32 

~--- .. 

12 

--- 19 

26 29 33 

39 

41 

42 

44 

--------

0.012 0.025 

0.140 

0.032 

0.220 o.ow~ 0.300 0.320 

Pump. 337 -.... - ~ ...... 14 26 38 42 ......... ---- 0.140 0.250 0.400 0.440 

Fig. 22 shows the number of revolutions per minute of the wind 

wheel for three loads. Fig. 23 shows the horsepower for these loads. 

VELOCITY OF WIND IN MILES PER HOUR. Comparing the USeful pump 

10 u; 20 25 horsepower of this mill with 

~ that of the 16-foot mill No. 9, 

A 

FIG . .2:3.-Diagram show~ng horsepower of mill 

No. 30. Curve AB shows the horsepower for a 

32 foot-pound load; CD, the power for a251 footpound load; EF, the power for a 337 foot-pound 

load; dotted curve shows maximum horsepower 

for best load. 

it will be seen that this mill is 

not so powerful as No. 9. The 

power of the Aermotor for low 

velocities is much greater than 

that of the Irrigator. 

liiill No. 31.-This is a 14-foot 

Elgin wooden power mill, manufactured at Elgin, Illinois. It 

works a rotary("'~onder) pump. 

The wind wheel is on a 48-foot 

wooden tower. It has 88 plane 

wooden sails, each 52 by 6 by 

3k inches, set at an angle of 37° 

to the plane of the wheel. It 

is a sectional vaneless wheel; 

in place of the vane there is a 

heavy counterpoise. The wheel 

is geared forward about 7.19 to 

1. The rotary pump is a 3 inch. It is on a well point 6 inches in 

diameter and 8 feet long; the point penetrates the water to a depth of 

8 feet. The lift was about 18 feet. The suction and discharge pipes 
MURPHY.] PUMPING MILLS TESTED. 51 

are each 3 inches in diameter. The discharge was 2 quarts per revolution of pump. The pump is manufactured by t,he National Pump 

Company, of Kansas City, Missouri. In a 15-mile to a 20-mile wind 

the windmill worked the pump before priming, but would not start it 

in that wind after priming. After several attempts of the mill to 

start the pump the pull13y turned on the shaft so that it could not be 

used. It was very evident thP~t the pump was too great a load for the 

mill. The owner stated that the mill would only run during a strong 

wind. 

Mill No. 32.-This mill is like the 12-foot Aermotor, the working 

parts of which are shown in fig. 7. It is on a 40-foot steel tower. 

The wheel has 18 curved sails, each 44 by 18! by 7! inches, set at an 

angle of 31 o to the plane of the wheel. The pump is of the Woodmanse type, a sectional view of which is shown in fig. 5, and has an 

8-inch cylinder and 12 inches stroke. It is in an open well. The depth 

to water was 14 feet, the lift 20 feet, and the discharge per stroke 7 

quarts. It is back-geared, 3! to 1. The water is pumped into a pond 

and used for irrigation. The mean barometric pressure was 27.9 

inches, the mean temperature 82° F. The results of the tests are as 

follows: 

Results of tests of rnill No. 32-12-foot Aerrnotor. 

[Load per stroke, 313 foot-pounds.] 

F Revolutions Strokes of Gallons 

Wind Useful horse- velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. power. 

I 8 miles _____ . __ . _ . ___ 17.7 5.3 9.3 0.047 1 12 miles . __ . ______ . _ . _ 49.3 14.8 2f). 9 

~J 15 miies _ . ___ . ________ 60.0 18.5 32.4 4 20 miles . _____ . ___ . ___ 73.0 22.0 38.5 5 

Mill No. 33--This is a 10-foot Woodmanse pumping mill on a 40-foot 

steel tower. The working parts are like those shown in fig. 4. The 

wheel has 24 curved sails, each 30t by 12t by 5t inches, set at an 

angle of 29° to the plane of the wheel. It is back-geared, 2t to 1. 

The pump is of the Woodmanse make (like that shown in fig. 5), with 

a 6-inch cylinder and 10 inches stroke. The depth to water was 14 

feet. The pump is on a well point 3t inches in diameter, 4 feet long, 

and 67 feet below the surface of the ground. ~.rhe suction pipe is 3t 

inches in diameter, t,he discharge pipe 6 inches in diameter. The lift 

was about 22 feet, the discharge per stroke 3! quarts. The water 

is pumped into a pond and used for irrigation. The mean barometric pressure was 27.9 inches, the mean temperature 88° F. 
52 THE WINDMILL. [No.41. 

The results of the tests are as follows: 

Results of tests of mill No. 33-10-foot Woodmanse. 

[Load per stroke, 173 foot-pounds.] 

I Revolutione I Strokes of Gallons Useful hor:l Wind velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. power. 

8 miles . _____ . ___ . ___ 8.7 3.5 3.3 0.020 12 miles ______________ 36.0 14.4 13.5 0.075 

L5 miles __________ ·--- 51.2 20.5 19.2 0.11~ 

Mill No. 35.-This is an 8-foot steel Dempster pumping mill, manufactured by the Dempster Manufacturing Company, of Beatrice, 

Nebraska, and is shown in Pl. XII. The tower is of steel, 30 feet to axis 

of wheel. The wind wheel has 18 curved sails, each 30-! by 14-! by 7 

inches, set at an angle of 27° to the plane of the wheel. It. is backgeared, 3 to 1. The well is an open dug well. The distance from the 

surface of the ground to the water was 39 feet. The water is pumped 

into a tank 22 feet above ground, and is /used for irrigation. The 

pump has an 8-inch stroke, a 3-!--inch cylinder, and 2-inch suction and 

discharge pipes. The lift was 58 feet, the discharge per stroke 1.1 

quarts. The mean temperature was 51 oF., the mean barometric pressure 28.9 inches. The results of the tests are as follows: 

Results of tests of mill No. 35-8-foot steel Dempster. 

[Load per stroke, 133.5 foot-pounds.] 

I Revolutions Strokes of Gallons 

Wind Useful hor:l velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minnte. power. 

12 miles . ____ . ________ 57.6 19.2 5.3 0.077 16 miles ___ . __________ 86.4 28.8 7.9 0.116 

I 

20 miles ___ . _________ . 99.9 33.3 9.2 0.13~ 

In a 15-mile wind the pump made 26 to 27 strokes per minute, and 

when the pump rod was uncoupled from the pump it made 34 strokes 

per minute in the same wind. Fig. 24 shows the number of strokes 

per minute for different wind velocities. This mill is heavily 

loaded-133 foot-pounds per stroke of pump. It starts at a wind 

velocity of about f) miles an hour, and as the wind increases the 

number of strokes increases rapidly at first, then more slowly. At 

25 miles an hour the number of strokes is 37 per minute. This mill 

is back-geared, 3 to 1, so that in a 25-mile wind the wind wheel makes 

111 revolutions per minute and has a circumference velocity of 46.5 

feet per second. 

Mill No. 36.-This is a 22-!-foot Eclipse wooden pumping mill, lift-
U. S. GEOLOGICAL SURVEY WATER -SUPPLY PAPER NO. 41 PL. XII 

VI EW OF M ILL NO. 35- 8-FOOT DEMPSTER. 
MURPHY.] PUMPING MILLS TESTED. 53 

ing wate'r into a tank for railroad purposes. The tower is of wood, 52 

feet to the axis of the wheel. 'rhe wind wheel has 136 plane sails, 

each 105 by 6 by 2 inches, set at an angle of 39° to the plane of the 

wheel. It works by direct VELOCITY OF WIND IN MILES PER HOUR. 

stroke. The well, which is 

open, is 20 feet in diameter; 

the depth to water was 19 

10 15 20 25 

~~~---~---~~--~--~-~ 

feet from the surface of the 

ground. The pump is p; 30 

double-acting, and has a 5 

4t-inch cylinder, 7 inches : 

stroke, and 2-inch suction ~ 2o,J-----+--.,.t--____;I---,.--::,IF.---+--t 

and discharge pipes. The "" ~ 

lift was 39 feet. The tank ~ w 

is 90 feet from the well. loJ-----,ft-.7'~--1----1-----4--1 

The discharge~ could not be 

measured, but as the packing of the pump was new it 

was approximately equal to 

twice the volume of the 

FIG. 24.-Comparative diagram showing results with 

mills No. 35 (8-foot Dempster) and No. 36 (22t-foot 

Eclipse). 

cylinder, or 0. 76 gallon per double stroke. The mean temperature 

was 58° F., the mean barometric pressure 29.43 inches. 'rhe results 

of the tests .are as follows: 

Ret>'Ults of tests of mill No. 36-22t-foot wooden Eclipse. 

[Load per stroke, 248 foot-pounds.] 

Revolutions Strokes of Gallons 

Wind Useful horse- velocity per hour. of wind wheel pump per pumped per 

per minute. minute. mmute. power. 

8 miles ..... _____ .. _. 4.8 4.8 3.8 0.036 

12 miles . _ ........... _ . _ 12.0 12.0 9.4 0.090 116 miles.. ___ . ______ .. 16.5 16.5 12.8 0.124 les. _____________ 20.0 20.0 15.6 0.150 

les . _ . ___ .... ____ 24.2 24.2 18.8 0.182 

Fig. 24 shows the strokes per minute at different wind velocities. 

The diagram is seen to be quite different from that of mill No. 35. 

The mill starts at a wind velocity of 6 or 7 miles an hour, and 

increases gradually to 24 strokes in a 25-mile wind. The circumference velocity of the latter is 46,5 feet per second, that of the former 

29 feet. The wind wheel of this mill is making 24 revolutions per 

minute; that of No. 35 is making 111 revolutions per minute in a 

25-mile wind. 

Mill No. 37.-This is a 12-foot steel Woodmanse Mogul like that 

shown in fig. 4. It pumps water into a pressure tank 9-! feet by 2t feet 

in a cellar and about 170 feet from the well. The pump and pressure 
54 'l'HR WINDMILL. (NO 41. 

ta11k are shown iu iig. 25. The 1.ower is of steel, and is 40 feet to the 

axis of the wheel. The wind wheel has 30 curved sails, each 37 by 13 

by 5.5 inches, set at an angle of 29° t.o the plane of the wheel. The 

well is 50 feet deep and 8 inches in diameter; the depth to water was 

42 feet. The pump has a 3-inch cylill(ler and 9 inches stroke. The 

disc~harge pipe is 1 inch in diameter, the suction pipe lt inches in 

FIG. 25.-Pump, pressure tank, and hydrnulic regulator of mill No. :17 - 12-foot Wood manse 

Mogul. 

diameter. The discharge per M.roke was 1.05 quarts. The load on 

the pump was equal to 43 feet head of water (the friction in about 

200 feet of l-inch pipe) and a compressed-air pressure the amount of 

which was recorded on a gage. The mean tempemture was 66° F., the 

mean barometric pressure 29.1 inches. The results of the tests are as 

follows: 
MURPHY.] PUMPING MILLS TESTED. 55 

m Results of tests of mill No. 37-12-foot steel Woodmanse Mogul. Number of •troke• of pump per min- ute at given wind velocities (per U'"'fnl 

velocities 

hor.epower (per at 

hour). 

given~ hour). 

00 

'"' ui ui ui 00 ,;, 00 00 I a:> 00 00 rti p, 00 <D a:> 00 ,.Sl ~ ,.Sl ,.Sl <D ,.Sl <D 

'0 <D ~ ] ] a:> 

Cll ] ] ] '§ s '§ :;;:: '§ '§ s 0 

~ ~ 0 ~ ~ s c-l ~ 

~ ~ 0 ~ 00 1:-l 00 ...... ...... co 

Ft.-lbs. 

lll7.7 18.4 24.5 29.3 34.2 38.0 0.022 0.053 0.071 0.083 0.0971l:J.108 ------ 12.2 19.0 23.3 26.7 29.0 ------- 0.094 0.146 0.180 0.205 0.223 

:::::: ::::::: ::::::: ~g:~ --~~~~- --~~--~- ::::::: ::::::: ::::::: &:i~ -~--~- --~:~--

Fig. 26 shows the number of strokes per minute for different wind 

velocities for four useful pump loads, viz, 43 feet, 43 feet plus 32 

pounds, 43 feet pluR 50 pounds, and 43 feet plus 75 pounds, or, 

reducing the pounds pressure to head in feet, the four useful loads 

are: 43 feet for the 

curve aa', 116 feet for 

the curve bb', 160 feet 

for the curve cc', and 

216 feet for the curve 

dd'. The effect of increased load on the 

number of strokes is 

well shown here. The 

effect of the hydraulic 

regulator may be seen 

in the curve cc', but it 

is shown to a greater 

extent in t,he curve 

dd'. 

Mt?l No. 38.-This 

~ 

);:1 

VELOCITY OF WIND IN MILES PER HOUR. 

10 15 20 25 

~r-----~------~------r-----~------~, 

~ oo~----+-----4-----~b7~---+----~n, 

~';, 

0 

rJJ 

[:01 

~ 

0 ~r------+--~-~~---r-~~-+---~~ 

~ 

10~--~_.------~-----=L-----~------~~ 

FIG. 26.-Diagram showing results with mill No. 37-12-foot 

W oodmanse Mogul. The curve aa' is for a useful pump load 

of 43 feet head; bb' is for a useful pump load of 116 feet head; 

cc' is for a useful pump load of 160 feet head; dd' is for a useful pump load of 216 feet head. The effect of the hydraulic 

regulator is shown in the curves cc' and dd'. 

is a 10-footWoodmanse wooden mill on a 30-foot wooden tower, and is 

used to pump water for stock. The wind wheel has 96 plane sails, 

eacb 34 by 3t by 1! inches, set at an angle of 38° to the plane of the 

wheel. The well is driven and is 107 feet deep; the depth to water 

was about 44 feet. The pump works direct and has a 2-!-inch cylinder 

and 4 inches stro;ke. The lift was about 50 feet, and the discharge 

per stroke of pump to gallon. 
56 THE WINDMILL. [No.41. 

The results of the tests are as follows: 

Results of tests of mill No. 38-10-foot wooden Woodmanse. 

[Load per stroke, 21 foot-pounds.] 

Revolutions Strokes of Gallons 

Wind Useful horse- velocity per hour. of wind wheel pump per . pumped per 

per minute. minute. minute. power. 

8 miles ----·-·-·---... 18 18 0.9 0.012 1 12 miles ... ___________ 29 29 1.5 0.019 16 miles ______________ 36 36 1.8 

~ 20 miles .... _ •• _______ 41 41 2.1 6 25 miles _______ .. _ . ___ 46 46 2.3 9 

Fig. 27 shows the number of strokes per minute for different wind 

velocities. This is a lightly loaded mill, working direct stroke. It 

VELOCITY 0~' WIND IN MILES PER HOUR. 

10 15 20 25 30 

~ ~ 301~-----+--~--+------+------+------4 

r-. 

0 

<11 

f";1 

~ 

~20 

~ 

FIG. 27.-Comparative diagram showing results with mills No. 38 (10-foot wooden Woodmanse) 

and No. 48 (30-foot wooden Halliday). 

starts in a 5-mile wind; the number of strokes increases very rapidly 

at first, and more slowly for high velocities. In a 30-mile wind the 

number of strokes per minute is 50. The circumference velocity 

of this wheel in a 25-mile wind is 24 feet per second. 

Mill No. 39.-This is a 10-foot Woodmanse direct-stroke iron pumping mill, used to pump water for stock. The tower is of iron, 35 feet 

to the axis of the wheel. The wind wheel has 18 curved sails, each 30 

by 12! by 7! inches, set at .an angle of 40° to the plane of the wheel. 

The pump is on a well point 24 feet below the surface of the ground. 

It has a stroke of 6 inches, a 3t-inch cylinder, and It-inch suction 

and· discharge pipes. The lift was about 27 feet, the discharge per 

stroke 1 quart. The results of the tests are as follows: 
MURPHY.) PUMPING :MILLS TESTED. 

Results of tests of mill No. 39-10-foot iron Woodmanse. 

[Load per stroke, 36 foot-pounds.] 

1 w;nd velocity •• r hour. RevoluHons I Strokes of Gallons Useful horse- of wind wheel pump per pumped per 

per minute. minute. minute. power. 

8 miles _____ . ________ 15 15 3.7 0.017 12 miles ______________ 30 30 7.5 0.034 

16 miles ___ ---------- 40 40 10.0 0.044 20 :miles ___ . __________ 47 47 11.7 0.052 

57 

I 

Mill No. 4.0.-Tbis is an 8-foot steel pumping mill manufactured by 

Fairbanks, Morse & Company. It is used to pump water for stock. It 

is on a 30-foot steel tower. The wind wheel has 18 curved sails, each 

29 by lot by 5 inches, set at an angle of 29° to the plane of the wheel. 

It is back-geared, 2t to 1. The pump is on a well point 20 feet below 

the surface of the ground. It has a stroke of 6 inches, a 3f-ineh 

cylinder, and lf-inch suct.ion and discharge pipes. The lift was about 

22 feet, and the discharge per stroke fo gallon. The results of the tests 

are as follows: 

Results of tests of mill No. 40-8-foot Fairbanks-Morse steel mill. 

[Load per stroke, 13 foot-pounds.] 

I Wind velocity per hour. 

Revolutions Strokes of Gallon' I of wind wheel pump per pumped per Useful horseper minute. minute. minute. power. 

8 miles _ .._____ . ______ 32.5 13.0 0.8 0.005 12 miles. ____________ . 55.0 22.0 1.5 0.009 16 miles. _____ . _______ 72.0 29.0 1.9 0.012 20 miles ______________ 85.0 34.0 2.3 0.014 

Mill No. 4.1.-This is a 12-foot Woodmanse direct-stroke iron pumping mill, used for pumping water for stock. The tower is of iron, 30 

feet to the axis of the wheel. The pump has a 3-inch cylinder and 6 

inches stroke. The wind wheel has 24 curved sails, each 36 by 14-! by 

7! inches, set at an angle of 39° to the plane of the wheel. The lift 

was 28 feet, and the discharge per stroke -k gallon. The results of the 

tests are as follows: 

Results of tests of mill No. 41-12-foot iron Woodmanse. 

[Load per stroke, 29 foot-pounds.] 

I Revolutions Strokes of Gallons 

Wind Usefulho:J velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. power. 

8 miles. _____ . _______ 14 14 1.7 0.012 12 miles _________ . ____ 25 25 3.1 0.022 

16 miles. -- --------· 33 33 4.1 0.029 20 miles ______________ 40 40 5.0 0.0~ 
58 THE WINDMILL. [No.41. 

JJ!b:ll1Vo. 42.-This is a 6-foot Ideal pumping mill on a 22-foot steel 

tower, and is· used for pumping water for stock. It is shown in Pl. 

XIII. The wheel has 12 curved sails, each 26 by 14t by 5 inches, set 

at an angle of 39° to the plane of the wheel. It is back-geared, 4 to 1. 

The well is a dug well; depth to water, 15 feet. The pump has a 3-inch 

cylinder and 6 inches stroke. The lift was 16 feet, the discharge per 

stroke 1 quart. The results of the tests are as follows: 

Re.~ults of tests of mill No. 4::!-G-foot Ideal. 

[Load per stroke, 35 foot.pounds.] 

~· 1' 

Revolutions ! 

I 

Strokes of Gallons 

md ve omty per hour. of wind wheel: pump per pumped per 

per minute. 

I 

minute. minute. 

8 miles ___________ ._ ·1 16 I 4 1.0 

12 miles.-_ . ___________ 52 13 3 ') •'-' 16 miles ____ . _________ 76 

I 

19 4.7 

20 miles ---- ---------I 92 23 5.7 

FIG. 28.-View of mill No. 4,3-10-foot Perkins. 

I 

I 

I 

I 

Useful ho rse-! 

power. 

-~--~ 

0.00 

0.01 

0.02 

4 

4 

0 

0.02 

~ 

This is the smallest mill yet tested. It is rather heavily loaded for 

its size; in fact, it is more heavily loaded than t,he 12-foot mill No. 

41. It is doing very good work for a mill of its size. 
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER NO. 41 PL. XIII 

VIEW OF MILL NO. 42-6-FOOT IDEAL. 
MURPHY.) PUMPING MILLS TESTED. 59 

1Jlill1Vo. 48.-This is a 10-foot Perkins direct-stroke pumping mill 

on a 32-foot steel tower, and is used 1o pump water for stock. The 

working parts are shown in fig. 28. The wind wheel has 30 curved 

sails, each 30 by lOt by 5 inches, set at an angle of 2\Jo to the plane 

of the wheel. The pump is on a well point 34 feet below the surface 

of the ground. It has a 3-inch cylinder and 4 inches stroke. rrhe 

lift was about 36 feet, the discharge per stroke t quart. rrhe exposure 

was not good. The results of the tests are as followR: 

Result.<s of test::; of mill No. J,S-10-foot Perkin8. 

[Load per stroke, 37 foot-pounds.] 

I :,::00!:~~~-~~~~-- Revolutions Strokes of Gallons Useful horse- of wind wheel pump per pumped per 

per minute. minute. minute. powero 

20 20 2.5 0.022 12 miles _____________ . 32 32 4.0 0.035 16 miles. _______ 41 41 5.1 0.045 

20 miles._ .. ___ ... __ . __ 45 45 5.6 0.050 

I -

Mill No. 45.-This is a 10-foot Eclipse direct-stroke pumping mill 

used to pump water for stock. The tower is of wood, 40 feet to the 

axis of the wheel. The wind wheel ·has 84 plane sails, each 36-! by 4 by 

1-! inches, set at an angle of 35° to the plane of the wheel. The well 

is a dug well; depth to water, 12 feet. The pump has a stroke of 6 

inches, a 3-inch cylinder, and lf-inch suction and discharge pipes. 

The lift was 14 feet, and the discharge per stroke 0.62 quart. The 

results of the tests are as follows: 

Results of tests of mill No. 1,.5-10-foot wooden Eclipse. 

[Load per stroke, 18 foot-pounds.] 

Revolutions Strokes of Gallons 

Wind Useful horse- velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. power. 

I 

8 miles __________ ~ ___ 18 18 2.8 0.010 1 12 miles ____________ ._ 28 28 4.3 0.014 16 miles _________ ~ ____ 32 32 5.0 !!J 20 miles ___ .. _________ . 35 35 5.4 8 25 miles __________ --. 38 38 5.9 9 

Mill ... Vo. 46.-This is a 10-foot Cornell direct-stroke wooden mill 

manufactured at Louisville, Kentucky, and is used to pump water 

for stock. The tower is of wood, 30 feet to the axis of the wheel. The 

wind wheel has 90 plane sails, each 36 by 4t by 1 t inches, set at an 

angle of 47° to the plane of the wheel. The well is a dug well; the 

water is only about 3 feet below the surface of the ground. The 

_pump has a 3t-inch cylinder and 4 inches stroke. The discharge 
60 THE WINDMILL. (N0.41. 

per stroke was 1 pint when pumping rapidly. The lift was 5j feet. 

The results of the tests are as follows: 

Results of tests of mill No. 46-10-foot wooden Cornell. 

[Load per stroke, 6 foot-pounds.] 

I Wll>d velocity per ho=. 

I I Revolutions Strokes of 

of wind wheel pump per pumped Gallons per I u se ~~ u orseper minute. minute. minute. i power. 

Smiles --- ------ ---- 16 16 2.0 0.003 12 miles ______ 25 25 3.1 0.004 16 miles ______________ 36 36 4.5 0.006 20 miles ______________ 42 42 5.2 Y!J 25 miles ______________ 48 48 6.0 7 30 miles _____ . ________ 52 .52 6.5 8 

Mill No. 47.-This is a 10-foot Dempster steel mill, like that shown 

in Pl. XII, on a 40-foot steel tower. The wind wheel has 24 curved 

sails, each 30f by 13t by 6t inches, set at an angle of 29° to t,he plane 

of the wheel. The pump is back-geared, 2! to 1, and has a 3-inch 

cylinder and 7 inches stroke. The well is open, 20! feet to water, and 

situated under the porch of a house. The mill is located 76 feet from 

the well. The cylinder is directly under the mill, in a chamber 4 feet 

by 4 feet, and 6 feet deep. The lower end of the cylinder was about 

12 feet vertically above the surface of the water in the well. The 

discharge per stroke was 1 quart when pumping rapidly. The lift 

was about 18 feet. The wind wheel of this mill is not well balanced, 

and the spring which holds it in the wind is not stiff. enough. The 

results of the tests are as follows: 

Result.~ of tests of mill No. 47-10-foot steel Dempster. 

[Load per stroke, 37 foot-pounds.] 

Revolutions Strokes of Gallons 

Wind Useful horse- velocity per hour. of wind wheel pump per pumped per 

per minute. minute. minute. power. 

I 8 rnlles .............. 37 13 3.2 0.014 1 12 miles _ _ _ _ _ _ _ _ _____ 66 23 5.7 0.026 I 16rniles ...•......... 89 31 7.8 

~HJ les _ _ _ _ _ _ . _______ 95 33 8.3 7 les ______________ 0 0 0 0 

A diagram which was platted for this mill shows that the curve 

drops at about 19 miles an hour, and reaches the axis line at 24 miles. 

Above 24 miles an hour the wheel is entirely out of the wind and does 

no work. On this diagram was also platted the number of strokes 

per minute of the 8-foot Dempster (No. 35), to show the effect of the 

different loads upon the number of strokes per minute. The 8-foot 

mill was found to be carrying more than three times the load that the 

10-foot mill was carrying. 
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER NO. 41 PL. XIV 

VIEW OF MILL NO. 48-30- FOOT HALLIDAY. 
MURPHY.) PUMPING MILLS TESTED. 61 

Mill No. 48.-This is a 30-foot Halliday wooden pumping mill on a 

70-foot wooden tower. It is owned by the city of Valley Falls, Kansas, 

and is used to pump water for the city supply. The mill and tower 

are shown in Pl. XIV. The sail area is arranged in two concentric 

rings. In the outer ring there are 192 sails, in the inner ring 144 

sails, each 43 by 4t by 3t inches, set at an angle of 25° to the plane of 

the wheel. There are two wells; one (11 feet in diameter) directly 

under the mill, and another (10 feet in diameter) near the bank of 

the river 375 feet from the mill. A 3-inch suction pipe connects the 

wells, and a 3-inch supply pipe leads from the lower well to the river. 

The pump is double-acting, and has a 4-inch cylinder and 11 inches 

stroke. The water is pumped directly into the distribution pipes, 

also into an elevated tank. The tank is of wood, 20 feet by 30 feet, 

and is 5,570 feet distant from the mill. Of the connecting pipe, 50 

feet is 3 inches in diameter, 1,200 feet is 4 inches in diameter, and 

4,300 feet is 6 inches in diameter. 'rhe bottom of the tank is 111 feet 

above the well platform. The lift or head at any time is, then, the 

distance from the well to the well platform and 111 feet plus the 

amount registered on the gage on the tank. The mean lift when 

the test was made was 135 feet. The cylinder capacity is 2.4 quarts, 

the measured discharge per double stroke 4.5 quarts. The mean 

temperature was 90° F., the mean barometric pressure 28.9 inches. 

The results of the tests are as follows: 

Results of tests of mill No • .48-30-joot wooden Halliday. 

[Load per stroke, 1,265 foot-pounds.] 

Revolutions 

Wind velocity per hour. of wind wheel 

per minute. 

Strokes of [ Gallons Useful horsepump per 'I pumped per minute. minute. power. 

8 miles___ __ ____ ____ 6 ---6-l 6. 7 0.23 

1

1 

12miles______________ 15 15 16.9 0.58 

...... 

_1_6_m __ il~es~---_--_-_-_--_-_-_-_--~-~-----2-0-~--~--2-0~-----2-2-.5---~-- 0 7~7 I 20 miles . __ . _. ___ .. __ . 24 24 27. 0 

25 miles. ____ . ____ .. ___ 28 28 31. 5 

~Phis windmill and pump had been in use about ten years. It furIIlishes enough water during nine months in the year, but during the 

months of July and August and part of June and September a steam 

engine is at times employed to work the pump. The cost of repairs 

to the mill and pump has been from $50 to $60 a year. The number 

of strokes per minute for different wind velocities is shown in fig. 27. 

This is the largest windmill pumping outfit that we have tested. 

It is interesting to compare its power with that of the smaller wooden 

mills and with that of the steel mills. 

Mill No. 51.-This is an 8-foot Monitor steel pumping mill on a 30-

foot steel tower (see fig. 29). The wind wheel has 18 curved sails, 

each 31t by 13 by 5 inches, set at an angle of 35° with the plane of 
62 THE WINDMILL (N0,41. 

the wheel. 'l'he well is a dug well; depth to water, 1St feet. The 

water is used for stock. The pump has a 3-inch cylinder, 6 inches 

stroke, and 1~ -inch suction and discharge pipes. The cylinder is 1 

foot above the lower end of the suction pipe, and is always under 

water. A peculiarity of this mill is that the downstroke of the pump 

FIG. 29.-Working parts of mill No. 51- 8-foot Monitor. 

is made in less time than the upstroke. The mill is back-geared, 

35 to 13, 13 of the cogs being passed over on the downstroke and 22 

on the upstroke. This arrangement makes the mill run easily and 

prolongs its usefulness. The wind wheel is held in the wind by the 

weight of the tail; there is no spring. The lift was 25 feet, the discharge 

per stroke 0. 7 quart. The mean temperature was 84 o F., the mean 
MURPHY.] R}-:SULTS OF TESTS OF PUMPING MILLS. 63 

barometric pressure 27.8 inches. The results of the tests are as follows: 

Results of tests of mill No. 51-8-foot steel Monitor. 

[Load per stroke, 36.5 foot-pounds.] 

r-- Revolutions Strokes of Gallons Useful horse- I Wind velocity per hour. of wind wheel pump per pumped per 

I 

per minute. minute. minute. power. 

.. I 

-----------

I 8 miles _____________ - 27 10 1.7 0.011 

I 

12 miles __________ . ___ 56 21 3.7 0.023 16 miles ______________ 81 30 5.2 0.034 I 20 miles _________ . ____ 91 34 6.0 0.037 

~ 

When the mill was running uncoupled from the pump, the pump 

rod made 24 strokes per minute in a 12-mile wind, i. e., the pump 

load of 36.5 foot-pounds per stroke reduced the number of the strokes 

of the pump rod from 24 to 21. 

For the purpose of ready" comparison the principal results of these 

tests of pumping mills have been tabulated. (See table on p. 64.) 

DISCUSSION OF RESULTS OF TESTS. 

In this discussion of the results of the tests of these pumping mills 

we wish to call attention to the principal facts shown by them. The 

explanation of some of the points is not easy. The useful work which 

a windmill will do at a given wind velocity depends on several factors, 

and it is difficult to measure or even estimate the value of each. If 

the mills could be tested under conditions easily controlled by the 

experimenter, the problem would be greatly simplified; but each mill 

is tested under its own conditions of pump, well, wind exposure, and 

atmosphere. A comparison of the results of the tests of pumping 

mills with the results of the tests of power mills throws much light on 

some of the facts (see Part II, pages 107 to 109, inclusive). A fact 

very evident from the following table is that the useful work done 

by windmills in pumping water is small. Only one mill, the largest 

(No. 48), is doing 1 horsepower of useful work in a 25-mile wind. 

The best 12-foot mill is doing less than 0.64 horsepower and the best 

8-foot mill less than 0.12 horsepower in a 25-mile wind. 
Results of tests of pumping mills. 

Useful Number of strokes of r:um~ per minute at Useful horsepower at given wind velocities 

No. of Name of mill. Size of Size of Lift of work given wind veloci ies per hour). (per hour). 

mill. mill. pump.b pump. per 8 12 16 20 25 30 8 12 16 20 25 30 stroke. miles. miles. miles. miles. miles. miles. miles. miles. miles. miles. miles. miles. --------------------------------------------- Feet. Inches. Feet. Ft.-lbs. 2 Woodmanse------------------ 12 9tx12 17.75 536.2 ----5:3- 5.2 16.0 20.3 23.3 25.3 --o~oof 0.085 0.260 0.322 0.379 0.411 3 Aermotor. -------------------- 12 9tx12 13.75 415.3 12.0 16.4 19.8 23.1 25.0 0.151 0.207 0.250 0.291 0.315 4 Ideal_------------------------- 8 5tx 8 12.00 50.0 -------- 10.2 19.3 25.3 28.1 25.0 .................. 0.015 0.029 0.038 0.043 0.038 5 Aermotor ________ -------------- 8 6x8 13.00 94.9 ................... 18.6 25.1 29.8 34.6 38.5 -------- 0.053 0.072 0.086 0.099 0.111 6 Gem-------------------------- 8 ()tx 8 9.60 77.6 -------- 12.4 17.9 22.0 25.4 28.5 .................. 0.029 0.042 0.051 0.059 0.065 7 Aermotor ______ --------------- 12 9tx12 15.50 461.9 ---28:o· 11.4 15.8 19.0 22.1 23.5 --o~6i3- 0.160 0.221 0.266 0.309 0.329 8 Star (a) ________ --------------- 10 3x5 30.00 15.0 30.0 ---i4T ""'i7:if ---i9:i3" ---2i:o- 0.014 9 Aermotor. ____ ---------------- 16 8 x16 44.25 1,013.0 --6:433- ··o:m· --6:ooi" ---.):644 """i4:i- 10.6 --.r6iil" 0.325 10 Ideal .... ---------------------- 8 2tx 6 33.00 22.8 25.0 33.3 ·--is:s· ---23.-3" ---25:o- 0.017 0.023 0.032 11 --6:600- ---o.-639 ----.do __ ----_---- __ ------------ 12 7tx12 45.00 843.7 -------- 4.8 12.7 --6:o25- 0.123 0.325 0.481 12 _____ do _______ ------------------ 14 9tx12 11.00 263.5 3.1 10.9 15.7 19.2 21.5 ---27.5" 0.087 0.125 0.153 0.172 -------- 13 Aermotor ______ ---- ____ . __ . ___ 12 10 x12 11.00 330.0 ................ 11.0 17.1 21.0 24.6 .................. 0.110 0.171 0.210 0.247 0.275 15 Gem·------------------------- 10 8x8 15.00 219.0 ---To- 7.8 11.9 14.7 14.6 -------- --6:oi2- 0.053 0.082 0.101 0.099 -------- 16 Halliday (a) ------------------ 10 6x8 16.00 100.0 22.6 33.9 42.7 52.5 ................. 0.067 0.103 0.130 0.159 -------- 17 Gem-------------------------- 12 8 x12 21.75 38.5 ·------- 6.0 12.8 17.3 .................. --·------ ................. 0.070 0.149 0.202 --0~ 074" . -- .. ---- 18 Ideal ____ ---------------------- 8 5tx 8 14.75 89.2 8.0 20.2 26.1 28.0 27.5 .................... 0.022 0.054 0.070 0.076 ----.......... 19 Gem __________________________ 12 10 x10 18.00 450.0 ----......... 6.2 11.9 14.7 16.0 -------- -------- 0.085 0.162 0.201 0.219 -------- 20 Jumbo (a) ··------------------- 15t 6 x12 14:.00 291.2 .................. ---i4:o- 5.3 10.7 17.5 .................... .................. ··o:ooo· 0.047 0.095 0.154 . .............. 21 Ha1liday(a) ------------------ 12 7tx 7 15.00 141.5 """i2:3- 28.5 37.3 44.6 ................ --6:002- 0.121 0.159 0.184 ......... ---- 25 Fairbanks---------- ......... ---· 8 2tx 4 8.50 5.5 29.2 37.3 38.0 33.3 ................. 0.005 0.007 0.008 0.005 ·------- 30 Irrigator (a)------_-·--------- 16 ---s-xi2- 14.00 ··ai:ro· ---"5:3" ---i4:s- ---i9:o· ---22:6- -------- ................ --6:o47" 0.14 0.25 0.40 0.44 ........ ---- 32 Aermotor ----------- __ -------- 12 20.00 -------- ----........ 0.131 0.170 0.195 .. ............. ................. 33 Woodmanse __ ---------------- 10 6 xlO 22.00 172.0 3.5 14.4 20.5 ---33:3- ................. ................. 0.020 0.075 0.110 --i)j34" ......... ---- -------- 35 Dempster--~--·--·------------- 8 Six 8 58.00 133.5 ----4:8- 19.2 28.8 ---24:2- , ............... ··o:006- 0.077 0.116 --6:is2- ................. 36 Eclipse (a)-------------------- w 4tx14 39.00 248.0 12.0 16.5 20.0 ·-·oo:o· 0.090 0.124 0.150 37 Woodmanse --·o:2-za __________________ 3x9 ··w:oo· 254.0 ---is:o· 12.2 19.0 2'd.3 26.7 --6:6i2- 0.094 0.146 0.180 0.205 38 .••.. do. (a)----------------··-· 10 2tx 4 21.0 29.0 36.0 41.0 46.0 -------- 0.019 0.023 O.O'Zfi 0.029 ................ 39 ...•. do ___________________ ------ 10 3tx 6 27.00 36.0 15.0 30.0 40.0 47.0 ................ ·---........ 0.017 0.034 0.044 0.052 ................. -------· 40 Fairbanks·------------------- 8 3tx 6 22.00 13.0 13.0 22.0 29.0 34.0 ................. .................. 0.005 0.009 0.012 0.014 .. .............. ................... 41 Woodmanse __________________ 12 3x6 28.00 29.0 14.0 25.0 33.0 40.0 -------- ........ ---- o.o12 0.022 0.029 0.036 ----........ ........ ........ 42 IdeaL. __ --·------------------- 6 3 X 6 16.50 35.0 4.0 13.0 19.0 23.0 ----........ .................. 0.004 0.014 0.020 0.024 -------- -------- 43 Perkins_··-------------------- 10 3x4 36.00 37.0 20.0 32.0 41.0 45.0 ................ ................ 0.022 0.035 0.045 0.050 .. ............... ......... ........ 45 Eclipse (a) ____________________ 10 3 X 6 14.00 18.0 18.0 28.0 32.0 35.0 ---43:6- ---52:o· 0.010 0.014 0.016 0.018 46 Cornell(a) ____ ---· ________ ---- 10 3tx 4 5. 70 6.0 16.0 25.0 36.0 42.0 0.003 0.004 0.006 0.007 --6:oor ---o.-oos 47 Dem.P,ster __ ----------- ____ ---- 10 3 X 7 18.00 37.0 13.0 23.0 31.0 33.0 0 0 0.014 0.026 0.03..'> 0.037 0 0 48 Halhday (a)------------------ 30 4 x22 135.00 1,265.0 6.0 15.0 20.0 24.0 28.0 -------- 0.23 0.58 0.77 0.92 1.07 -- ----- 51 Monitor.-----_.--------------- 8 3x6 25.00 36.5 10.0 21.0 30.0 34.0 ................ -.. -........ ~ 0.011 0.023 0.034 0.037 .. ............... ........ ...... ... 

a Wooden mills. b Inside diameter of cylinder by length ot stroke. 
MURPHY.) RESULTS OF TESTS OF PUMPING MILLS. 65 

From the foregoing table it will be seen that mills of the same size 

differ very much in the amount of useful work, and that some of the 

larger mills are doing very little more ·work than some of the smaller 

ones. Nos. 4 and 18, for example, are the same size and make (the 

wells, however, are very different), but the latter is doing three or 

four times more work than the former. The 12-foot mill, No. 11, is 

doing nearly as much useful work as the 16-foot mill, No. 9, and three 

or four times more work than the 14:-foot mill, No. 12, while it is doing 

300 per cent more work than No. 21. 'rhe 15-!-foot Jumbo will probably do little more work during the season t,han a good 8-foot mill. 

RELATION BETWEEN WIND VELOCITY AND STROKES OF PUMP. 

Figs. 6, 10, 11, 12, 13, 15, 17, 18, 19, and 21 show graphically the 

relation between the wind velocity (in miles per hour) and the strokes 

of the pump. The curves, as will be noted, differ considerably; but 

wHh the exception of fig. 19, for mill No. 20, they agree in that they 

rise rapidly, reaching the highest point at wind velocities of from 13 

to 19 miles. From that point they descend slowly. They differ much 

in the position of the beginning of the curve, or the v~locity required 

to start the mill. Some will run in an 8-mile wind, while others require 

a 10-mile or a 12-mile wind to start them. Some rise less rapidly than 

others, a notable case being mill No. 11. Some descend much more 

rapidly than others after reaching the highest point. This is especially 

true of the 8-foot Ideals. Mill No. 20 required a 14-mile wind to start 

it, and does not appear to have a maximum. The shape of the curve, 

especially the position of its initial point, is due to the load on the 

pnmp, or the number of foot-pounds per stroke. An increase in the 

load moves the curve to the right and raises it higher. This will be 

more clearly shown in, Part II (see discussion on 12-foot power mill No. 

27, pp. 86-89). The height and position of the highest point depend 

on the tension of the spring, or the weight which holds the mill in the 

wind. The greater the tension the higher the summit and the farther 

it is to the right; the less the tension in the spring the steeper the 

descent from the highest point. The gearing-i. e., the mechanism 

which causes the pump to make a stroke to each revolution of the 

wheel, or a stroke every second or third revolution only-modifies the 

curve. In mills with a direct stroke the curve is much higher and 

is farther to the right than in back-geared mills, as shown by a comparison of the curves of mills Nos. 3 and 21, shown in figs. 10 and 2L 

USEFUL WORK OF PUMPING MILLS. 

The relation between wind velocity and horsepower is shown graphically, for five 12-foot mills in fig. 30, and for four 8-foot mills in fig~ 

31. Examining the five curves of fig. 30, we see that No. 11, the one 

which gives the greatest horsepower, bas the heaviest load and 

requires the greatest wind velocity to start it. No. 2 has about 

IRR 41-01--5 
66 THE WINDMILL. [No.41. 

five-eighths of the load of No. 11, does less work, and requires about 

the same wind velocity to start it. No. 3 has a lighter load than No. 

2, and will start in a wind of about 7 miles an hour. No. 19 has a 

little heavier load than No. 3, and does much less work at all velocities. The latter requires a 9-mile or a 10-mile wind to start it, while 

the former will start in a 7-mile or an S-mile wind. No. 21 is doing 

the least work of the five, and requires about an 11-mile wind to start 

it. It is a wooden mill working direct stroke, while the others are 

steel mills and back-geared. 

VELOCITY OF WIND IN MILES PER HOUR. 

10 15 20 25 

. 70 

.60 

.50 

~ 

f>i1 

!:: 

0 

~ .40 00 

~ 

0 

~· 

~ 

~ .30 ~ 

0 

s 

z 

~ 

.20 

FIG. 30.-Diagram showing relation between horsepower and wind velocity for five 12-foot mills. 

It must be understood that in this comparison no COlTection or 

allowance is made for the difference in temperature and barometric 

pressure, nor for the fact that in the case of Nos. 11 and 19 the pumps 

are on well points, while in the others they are in open wells. 

It will be seen that none of t,he curves in fig. 30 reach a maximum 

below 30 miles an hour. They do, however, for some higher velocities, since the work per stroke of pump is nearly constant for each 

pump for all velocities, though not the same for one pump as for 

·another. The curves also give the relation between wind velocity and 

the number of strokes of pump per minute. 

In fig. 31 the curve for No. 18 is seen to reach a maximum at about 

25 miles an hour. The others reaeh their maximum points at veloci-
lllURPHY.] RESULT~ 0~' TESTS OF PUMPING MILLS. 67 

ties of about 30 miles an hour. These maximum points are points of 

. greatest speed, and are produced by a reduction of wiBd area, the wind 

wheel turning out of the wind. This make of mill is seen to "govern," or turn out of the wind, at a lower velocity than other makes. 

· Comparing the curves in fig. 31, we see that the pump doing the 

most work at high wind velocities is No. 5, which is also the one 

most heavily loaded. The principal differences between Nos. 4 and 

18, the pumps doing the most and the least work for velocities less 

than 22 miles an hour, are in the load and the well. No. 4 has fiveninths of the load of No. 18, and is on a well point. The two pumps 

doing the least work are on well points. 

VELOCITY OF WIND IN MILES PER HOUR. 

10 15 20 25 30 

_, .1 0 - tolo'& ......... ~ 

/ ~ v ~ 

~ 

v v 

~ - ;--_.-4 

/ / ~ ~ 

~ ~ ....._ 

1/ II' / ~ lr- ~ 

/ v-- ~ 

v /"" 

.02 

FIG. 31.-Diagram showing relation between horsepower and wind velocity for four 8-foot 

mills. 

Mill No. 25 is used to pump water for stock. Comparing it with, 

say, No.5, we find that its load is about five-ninths as great, and that 

it is doing about one-tenth as much work as the latter. It will start 

with a wind velocity of about 6 miles an hour, while the latter requires 

a wind velocity of about 8.5 miles an hour. 

It is interesting'· to compare the results of Nos. 35 and 36. The 

former is an 8-foot back-geared steel mill, heavily loaded; the latter is 

a 22.5-foot direct-stroke mill, lightly loaded. rrhe wind exposure of 

both is ve:ry good. The discharge per stroke of No. 35 is 1.1 quarts, 

that of No. 36 about 3 quarts. rrhe lift of the former is 58 feet, the lift 

of the latter 39 feet. The load per stroke of the former is 133 footpounds, that of the latter 248 foot-pounds. No. 35 starts in about a 
68 THE WINDMILL. (NO 41. 

9-mile wind, No. 36 in a 6-mile wind. In an S-mile wind the former 

is doing no work, the latter is making 4.8 strokes per minute; but in 

a 12-mile wind the former is making 19 strokes per minute, the latter 

only 12; for all higher velocities the former is making 60 per cent 

more strokes than the latter. For wind velocities above 12 miles an 

hour the horsepower of the 22.5-foot mill is only from 7 to 1'7 per cent 

greater than that of the 8-foot mill. The difference is really not so 

great as this, as the actual discharge is not so great as we have 

supposed. 

PRESSURE-TANK SYSTEM, 

Mill No. 37 is of special interest, in that the water is forced into a 

pressure tank instead of into an elevated tank. This system is said 

to be in use to some extent in the Eastern States, and is just coming 

into use in t~e West. The advantage claimed for it is that the tank 

can be placed in a cellar or under ground, where it will not freeze, 

instead of on an elevated structure. A hydraulic regulator is used, 

which causes the mill to turn out of the wind when the pressure in 

the tank reaches a certain amount. In this case the tank, which is 

located in a cellar, is 2 feet in diameter and 9.5 feet long; it is about 

170 feet from the well and about 43 feet above the surface of the 

water 'in t,he well. The discharge (1.05 quarts per stroke) is pumped 

into the tank, then forced by the confined air through a l-inch iron 

pipe to the hydrants, then through a line of rubber bose to the desired 

point. The pressure in the tank diminishes with the reduction in the 

quantity of water in it. For different volumes of air it is as follows: 

Pressures in tank for different volumes of ai1·. 

I------~A~ir_v_o_lu_m_e_. ______ 1 __ P_rM,nre. I 

Barrels. Pounds. 

11. 1 --. -·------ --- ----- -

5.6 --------· ------ ·--- 3.7 --·-· -·------------- 2. 8 - ---. -- ---- -- . --- .. 2. 2 - . - --- . ---- . - -. ----

~:::::::::::::::::: 

0 

14.7 

29.4 

44.1 

58.8 

73! I 

The objection to this system can easily be seen from this table. 

When the pressure is 103 pounds per square inch the withdrawal 

of 0.2 barrel of water from the tank lowers the pressure to 88.2 

pounds, and the withdrawal of an additional 0.3 barrel lmvers the 

pressure to 73.5 pounds; in other words, the withdrawal of a half barrel of water when the pressure is 103 pounds lowers the pressure 30 

pounds. We found, on trial, that when the pump was not working 

(no wind), and the pressure was at 59 pounds, one bose stream through 

a !rinch nozzle reduced the pressure to 50 pounds in one minute and 
MURPHY.] RESULTS OF TESTS OF PUMPING MILLS. 69 

to 45 pounds in two minutes. In seven minutes it fell to 30 pounds, 

and in seventeen minutes from the time of opening the cock it fell to 

20 pounds. In a 20-mile to 30-mile wind, and with one hose stream 

running, the pump kept the pressure in the tank at about 30 pounds. 

Where only a small amount of water is needed at a time this system 

will probably give satisfaction. By the use of a larger tank more 

water can be obtained for a given reduction of pressure. 

It will be noticed that this is the same size and make of mill as No. 

2, but that it is altogether different from No. 41. No. 2 is more heavily 

loaded than No. 37. The heaviest load on No. 37 is 472 foot-pounds 

per stroke of pump; the heaviest load on No. 2 is 536 foot-pounds per 

stroke. No. 2 is doing the most useful work, but the hydraulic regulator acts on No. 37 to turn it partly out of the wind for the load 43 

plus 75 pounds. No. 41 is doing very little work, but it is lightly 

loaded and working direct stroke. 

COMPARISON OF THREE PUMPING AERMOTORS. 

Comparing the 16-foot Aermotor No. 9, the 12-foot Aermotor No.3, 

and the 8-foot Aermotor No. 5, a diagram was_piotted of the horsepower of these three mills, drawn to the same scale. rrhey were found 

to start at about the same wind velocity, viz, 7 miles an hour, which 

indicates about the same total load. In a 25-mile wind the 8-foot 

mill was found to be yielding 0.1 horsepower, the 12-foot mill 0.29 

horsepower, and the 16-foot mill 0.6 horsepower. In other words, 

the 12-foot mill was doing about t.hree times and the 16-foot mill 

about six times more work than the 8-foot mill. The conclusion can 

not be drawn from this that the powers of the mills are to each other 

in these ratios, since the pump efficiencies are not the same. 

USEFUL WORK OF TWO PUMPING MILLS IN A GIVEN TIME. 

The useful work which two pumping mills of the same wind area, 

exposure, pump efficiency, and general chara<>ter will do depends 

on the load on the mill and the wind velocity. If the mill is heavily 

loaded it will do more work at wind velocities of 12 or more miles 

an hour and less work at lower velocities than one of lighter load. 

The useful work done in a given time is t.he product of the work 

done per hour at the mean velocity n1.ultiplied by the number of 

hours. If the mean velocity at a given place is low, the mill load 

must be less for maximum work than that at a place where the mean 

velocity is higher. To illustrate this fact, we will use the results of 

the tests of two 12-foot pumping mills-No. 11, heavily loaded and 

giving a greater horsepower at high wind velocities than any other 

mill tested, and No. 3, giving the greatest power at low velocities. 

The useful work per st.roke of pump is 844 foot-pounds for No. 11 

and 415 foot-pounds for No. 3. ,.fhe useless work of the former is 

greater than that of ·~;he latter, since the pump of the former is on 
70 THE WINDMILL. [N0.4!. 

two well points, while the pump of the latter is in an open well. The 

relation between the horsepower and the wind velocity is shown in 

fig. 30. The curves are seen to cross each other at a wind velocity of 

12.5 miles an hour. For less velocities than that No. 3 is doing more 

work per hour than No. 11, and for greater velocities No. 11 is doing 

more work than No. 3. If the velocity were, say, not more than 13 

miles an hour, it is very evident that mill No. 3 would do more work 

in a given time than mill No. 11. 

There is no record of wind movement at Garden, Kansas (where most 

of these tests of pumping mills were made), for any considerable length 

of time. There is one, however, for Dodge, 50 miles east of Garden, 

kept by the United States Weather Bureau, which may be used for 

this purpose. The fol].j..wing table gives the number of_ hours per 

month for the six months April to September, for the years 1889 to 

1895, inclusive, when the wind movement was, respectively, 0 to 5, 6 to 

10, 11 to 15, 16 to 20, 21 to 25, 26 to 30, 31 and more miles per hour. 

Mean wind movement at Dodge, Kansas, for the seven years 1889 to 1895 . 

.. Month. 0-5 6-10 11-15 

I 

16-20 21-25 26-30 31 and 

miles. miles. miles. miles. miles. miles. greater. 

---

Hours. Hours. Hours. Hours. Hours. Hours. Hours. 

April ..... __ . 116 175 157 113 76 43 40 

May ......... 116 195 168 120 74 39 32 

June .... ____ 120 187 139 111 86 49 28 

July_ -- ~ .. --- 144 218 176 117 57 23 9 

August ....... 178 230 152 99 112 18 5 

L?be<-_1~ 182 152 93 75 34 

Mean... 140 ~: I -198 -157J-109' -;-j-34 

It will be seen from this table that the wind velocity at Dodge is 5 

miles or less per hour for 140 hours per month. During this time 

neither of these mills (Nos. 3 and 11) will do any work, as neither 

will start in a 5-mile wind. 

The velocity is from 6 to 10 miles an hour for 198 hours a month. 

Mill No.3 will start in about a 7-mile wind, and hence will run about 

four-fifths of this time, or 158 hours. No. 11 requires 11.5 miles of 

wind to start it, and will do no work during this time. 

The velocity is 11 to 15 miles an hour for 157 hours during the month. 

No. 3 will work all of this time, and No. 11 about nine-tenths of the 

time, or 141 hours. 

Both mills will run at all higher velocities. At Dodge, mill No. 3 

will run (if in the wind) about 75 per cent of the time, and No. 11 

about 51 per cent of the time. For eonvenience, these results have 

been tabulated. 
MURPHY.] RESULTS OF TESTS OF PUMPING MILLS. 71 

Comparative results of tests of two pnmping mills. 

Mill No.3. 

Wind velocities, 

miles per hour. Hours per Horsemonth. power. 

6to10 _______ 158 0.067 11 to 15 . ____ . 157 0. 168 16 to 20 . _____ 109 0.230 

21 to 25 ------ 72 0.277. 

26 to 30 __ . __ . 34 0.308 

31 and greater 22 0.320 -----· ----- Total ~ .. - - ---------- - "'- ... -- .. - --

Mill No.ll. 

~ Product. H~~~t~~ 

10.6 0 

26.4 141 

25.1 109 

19.9 72 

10.5 34 

7.0 22 -------

99.5 1·- ·------- I 

Horsepower. 

0.00 

0.19 

0.40 

0.56 

0.63 

0.64 

----

-... -- -- ~. 

p 

,_ 

26.8 

43.6 

40.3 

21.4 

14.1 I 

146.2 I 

The second and fifth columns in this table give the number of hours 

during the mean mon~h that each mill will run with a wind velocity 

of from 6 to 10 miles an hour. The third and sixth columns give the 

horsepower for the mean velocity; for example, 0.168 is the horsepower for No.3 at a wind velocity of 13 miles an hour, and 0.19 is the 

horsepower for No. 11 at the same velocity. The fourth and seventh 

columns (the product of the numbP.r of hours and the horsepower) 

give the horsepower that each mill will yield during the month. It 

will be seen that No. 11 is doing 31 per cent more useful work than 

No. 3. If this ~omparison be made for the month of August, it will 

be found that No. 11 will do 26 per cent more useful work during that 

month than No. 3. 

PROPER LOAD. 

It will be seen from what. has just preceded, that the useful power 

of a pumping mill depends to a great extent on its load. If the water 

is needed constantly and there is little or no storage, as in the case of 

water for stock, the mill must be lightly loaded, and the useful work 

it will do is small. If, however, there is plenty of storage, the mill 

will pump the largest amount of water if heavily loaded. If there 

were some automatic device for increasing the load on the mill as the 

wind velocity increases, the problem of proper load would be solved. 

But such a device seems difficult to construct. 

The following table gives data for back-geared steel irrigating mill 

and good pumps for use in the semiarid regions of the 'Vest, especially 

for Kansas and Nebraska. 

Data regarding mills and pumps for use in semiarid regions. 

Diam- Load Quantity Cylin- Starting Speed Dis- Disdeliv- wind per min· charge charge eter of per 

e::r~~~~ Lift. derca- velocity ute in 

mill. per per 24 stroke. pacity. (per 20-milt> hour). wind. hour. hours. ! -- Fe.et. Ft.-lbs. Quarts. Feet. Inches. Miles. Strokes. Gallons. i Ao.-e·ft. 8 125 2.0 30 4.5x 8 9 27 810 0. 059 

12 600 9.6 30 sx12 8 to 9 20 • 2, 880 0. 212 

16 1,100 17.6 . 30 9xl6 7 to 8 16 4:,224 0.311 
72 THE WINDMILL. [No.41. 

For half this lift, <?r 15 feet, the cylinder capacity should be nearly 

doubled, and for double the lift the cylinder capacity should be about 

half that given in the table; 

In Part II of this paper, published as Water-Supply and Irrigatioi1 

Paper No. 42, will be found a discussion of the writer's experiments 

with power mills, a comparison of pumping mills with power mills, a 

discussion of the effect of tension of spring on the horsepower of 

mills, a mathematical discussion of the tests of two Aermotors, a dismission of the action of air on the sail of an Aermotor, a discussion 

of the useful work of two power mills in a given time, discussions of 

the results of tests of a Jumbo mill and of a Little Giant mill, a comparison of the Little Gi~nt and Jumbo mills, a comparison of the 

Little Giant mill and -the s:.foot Aermotor, a discussion of the indicated and true velocities of windmills, a comparison of the writer's 

experiments with those of other experimenters, and economic considerations. 

[For index see end of Part II, Water-Supply Papar No. 42.] 

0 
1S93. 

Sixteenth Annual Report of the Unitecl States Geological Survey, 1894-95, Part II, 

Papers of an economic character, 1895; octavo, 598 pp. 

Contains a paper on the public iands and their water supply, by F. H. Newell, illustrated 

by a large map showing the relative extent and location of the vacant public lands; also a report on the water resources of a portion of the Great Plains, by Robert Hay. 

A geological reconnaissance of northwestern Wyoming, by George H. Eldridge, 

1894; octavo, 72 pp. Bulletin No. 119 of the United States Geological Survey; 

price, 10 cents. 

Contains a description of the geologic structure of portions of the Big Horn Range and 

Big Horn Basin, especieJ}y with reference to the coal tielcls, and remarks upon the water SUJ>ply and agricultural po"sibilitie•. 

Report of progress of the division of h.rdrography for the calendar years 1893 and 

1894, by F. H. Newell, 1895; octavo, 176 pp. Bulletin No. 131 of the UniteJ 

States Geological Survey; price, 1() cents. 

Contains results of stream measurements at various pointK, mainly within the arid region, and records of wells in a number of counties in western Nebraska, western Kansas, and eastern Colorado. 

1S96. 

Seventeenth Annual Report of the United States Geological Survey, 18()5-96, Part 

II, Economic geology and hydrography, 18()6; octavo, 864 pp. 

Contains P>~pers on "The underground water of the .Arkansas Valley in eastern Colorado," by G. K. Gilbort: •• rrhe water resources of Illinois," by Frank Leverett, and "Preliminary report on the artesian waters of a portion of the Dakotas," lJy N.H. Darton. 

Artesian-well prospects in the Atlantic Coastal Plain region, by N. H. Darton, 

1896; octavo, 230 pp., HJ plates. Bulletin No.1il8 of the United States Geological Survey; price, 20 cents. 

Gives a description of the geologic conditions of the coastal region from Long Island, 

N.Y., to Georgia, and contains data relating to many of the deep wells. 

Report of progress of the division of hydrography for the calendar year 1895, by 

F. H. Newell, hydrographer in charge, 1896; octavo, 3-16 pp. Bulletin No. 140 

of the United States Geological Survey; price, 25 cents. 

Contains a description of the instruments and methods employbd in measuring streams and the results of hydrographic investigations in various parts of the United States. 

1S97. 

Eighteenth Annual Report of the United States Geological Survey, 1896-()7, Part 

IV, Hydrography, 1897; octavo, 756 pp. 

Contains a "Report of progress of stream measurements for the calendar year J8n6," by Arthur P. Davis; "The water resources of Indiana and Ohio," by Frank Leverett; "N<•w 

developments in well bering and irrigation in South Dakota," by N.H. Darton, and" Reservoirs for irrigation," by J. D. Schuyler. 

Hi99. 

Nineteenth Annual Report of the United States Geological Survey, 1897-98, Part 

IV, Hydrography, 18()9; octavo, 814 pp. I 

Contains a "Report of progress of stream measurements for the calendar ynar 18D8," 

by F. H. Newell and others; "The rock waters of Ohio" by Edward Orton, and "AJ. Jreliminary report on the geology and water resources of Nebraska west of the one hun red 

and third meridian," by N.H. Darton. 

1900. 

Twentieth Annual Report of the United States Geological Survey, 181>8-!l!l, Part 

IV, Hydrography, 1!JOO; octavo, 660 pp. 

Contains a "Report of progress of stream measurements for the calendar yoar 18U8," by F. H. Nowell, and "Hydrography of Nicaragua," by A. P. Davis. 

WATER-SUPPLY AND llUtiGATION PAPERS, 1896-1900. 

This series of papers i~ designed to present infamphlet form the results of stream meas- urements and of special investigations. A list o these, with other information, is given on the outside (or fourth) page of this cover. · 

Survey bulletins can be obtained only by prepayment of cost, as noted above. 

Money >~houlcl be transmitted by postal money order or express order, made payaula to the Director of the United :;!tates Geological Survey. Postage stamps, 

checks, ancl drafts can not be accepted. Correspondence relating to the publications of the Survey should be addressed to The Director, United States Geological Survey, Washington, D. C. 

IRR 41 
WATER-SUP~Y AND IRRIGATION PAPERS. 

1. Pumping water for irrigation, by Herbert M. Wilson, 1896. 

2. In-igation near Phcenix, Arizona, by Arthur P. Davis, 1897. 

3. Sewage irrigation, by George W. Rafter, 1897. ~ 

4. A reconnaissance in southeastern Washington, by Israel C. Russell, 1897,' 

5. Irrigation practice on the Great Plains, by E. B. Cowgill, 1897. 

6. Underground waters of southwestern Kansas, by Erasmus Haworth, 1897. 

7. Seepage waters of northern Utah, by Samuel Fortier, 1897. 

8. Windmills for irrigation, by E. C. Murphy, 1897. 

9. Irrigation near Greeley, Colorado, by David Boyd, 18()7. 

10. Irrigation in Mesilla Valley, New Mexico, by F. C. Barker, 1898. 

11. River heights for 1896, by Arthur P. Davis, 1897. 

12. Underground waters of southeastern Nebraska, by N.H. Darton, 1898. 

13. Irrigation systems in Texas, by W. F. Hutson, 1898. 

14. New tests of pumps and water lifts used in irrigation, by 0. P. Hood, 18!l8. 

15. Operations at river stations, 1897, Part I, 1898. 

16. Operations at river stations, 1897, Part II, 1898. 

17. Irrigation near Bakersfield, California, by C. E. Grunsky, 1898. 

18. Irrigation near Fresno, California, by C. E. Grunsky, 1898. 

19. Irrigation near Merced, California, by C. E. Grunsky, 1899. 

20. Experiments "\vith windmills, by Thomas 0. Pen-y, 1899. 

21. Wells of northern Indiana, by Frank Leverett, 1899. 

22. Sewage irrigation, Part II, by George W. Rafter, 1899. 

23. Water-right problems of Bighorn Mountains, by Elwood Mead, 1899. 

24. Water resources of the State of New York, Part I, by George W. Rafter,189!l. 

25. Water resources of theStateofNewYork,Part II, by George W.Rafter, 1899. 

26. Wells of southern Indiana (continuation of No. 21), by Frank Leverett, 1899. 

27. Operations at river stations, 1898, Part I, 1899. 

28. Operations at river stations, 1898, Part II, 1899. , 

29. Wells and windmills in Nebraska, by Erwin Hinckley Barbour, 1899. 

30. Water resources of the Lower Peninsula of Michigan, by Alfred C. Lane, 1899. 

31. Lower Michigan mineral waters, by Alfred C. Lane, 1809. 

32. Water resources of Puerto Rico, by H. M. Wilson, 1()00. 

33. Storage of water on Gila River, Arizona, by J. B. Lippincott, 1900. 

34. Geology and water resources of southeastern S. Dak., by J. E. Todd, 1900. 

35. Operations at river stations, 1899, Part I, 1900. 

36. Operations at river stations, 1899, Part II, 1900. 

37. Operations at river stations, 1899, Part III, 1900. 

38. Operations at river stations, 1899, Part IV, 1900. 

39. Operations at river stations, 1899, Part V, 1900. 

40. Tho Austin dam, by Thomas U. Taylor, 1900. 

41. The windmill: its efficiency and economic use, Part I, byE. C. Murphy, 1901. 

In addition to the above, there are in various stages of preparation other papers 

relating to the measurement of streams, the storage of water, the amount available 

from underground sources, the efficiency of windmills, the cost of pumping, and 

other details relating to the methods of utilizing the water resources of the country. Provision has been made for printing these by the following clause in the 

sundry civil act making appropriations for the year 18()6-97: 

Provided, That hereafter the reports of the Geological Survey in relation to the 

gaging of streams and to the methods of utilizing the water resources may be 

printed in octavo form, not to exceed 100 pages in length and 5,000 copies in num- ber; 1,000 copies of which shall be for the official use of the Geological Survey, 

1,500 copies shall be delivered to the Senate, and 2,500 copies shall be delivered to 

the Houseof Representatives, for distribution. (Approved June 11, 1806; Stat. L., 

vol. 29, p. 4133.] 

The endeavor is made to send these pamphlets to persons who have rendered 

assistance in their preparation through replies to schedules or who have furnished 

data. Requests made for a certain paper and stating a reason for asking for it are 

granted whenever practicable, but ij; is impossible to comply with general 

demands, such as to have all of the series sent. 

Application for these papers should be made either to Members of Congress or to 

THE DIREOTOR, UNITED STATES GEOLOGIOAL SURVEY, WASHINGTON, D. 0. 

IRR 41