# Popular Science Monthly/Volume 10/February 1877/Gas Manufacture and Gas Companies

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* GAS MANUFACTURE AND GAS COMPANIES.
CONDENSED FROM THE BOSTON REPORT
By WILLIAM E. SIMMONS.
THERE are three kinds of gas, named after the substances from which they are obtained, as coal, petroleum (or naphtha), and water gas. The first two are produced by destructive distillation of coal and petroleum, or naphtha, the last by passing a current of steam over a bed of incandescent anthracite. Coal-gas is the kind in general use, petroleum or naphtha gas being used chiefly as an enricher; and water-gas, used in only a few places and for a comparatively short time, is as yet on its trial. The general principles involved in the manufacture of each kind of gas will first be noticed; then the relative merits of the products will be considered in regard to quality, cost of manufacture, and respective peculiarities; and, finally, a comparative view will be taken of several leading companies; after which the relationship of gas companies to municipalities, and the subject of competition, will be examined.
When coal is subjected to high heat in a closed vessel, certain gases and vapors are evolved, some of which are combustible, and some, like steam, condensible, a residue of charcoal or coke being left behind. This process is termed destructive distillation, and the property displayed by coal is common to all vegetable and animal substances; but only coal and petroleum have been used economically in the production of illuminating gas on an extensive scale. The distillation is the most important operation in the manufacture, but it is necessary to remove from the gas, before it is fit for burning, the condensible vapors, as tar, water, etc.; and those non-condensible gases, as carbonic anhydride (carbonic acid), which either largely diminish the. illuminating power, or which give rise, in the burning of the gas, to injurious products of combustion, such as sulphuretted hydrogen and ammonia. The removing of these very materially affects the cost of production. The distillation is effected in iron or clay ​retorts, from three to seven of which, according to circumstances, are heated with one fire of coke to a cherry-red (1,478° to 1,830° Fahr.) for iron, or to an orange or white heat (2,000° to 2,300° Fahr.) for clay retorts; 160 to 260 pounds of coal constitute the charge for a single retort, and the distillation continues uninterruptedly for four to four and a half hours. The outer layers of the charge, being suddenly raised to a high temperature, evolve vapors which contain a large amount of carbon. These, in passing through the retort, are converted into fixed gases of a high illuminating power. The inner parts of the charge, undergoing distillation more slowly, give out vapors which, in passing through the highly-heated coke on the surface, are more completely decomposed than the first evolved, and are, therefore, of a lower illuminating power. It has been shown, for example, by Mr. C. D. Lamson, of the Boston Gas-Works, that the illuminating (or candle) power of the gas diminishes in a rapidly-increasing ratio with each half-hour of the distillation; and also that, after the third half hour, the quantity of gas produced similarly decreases. The largest quantity, as well as the richest gas, is, therefore, obtained in the first part of the distillation. By candle-power is meant that the gas, burning at the rate of five cubic feet per hour, will give as much light as the stated number of standard sperm-candles burning at the rate of 120 grains per hour, or two grains per minute.
The gas passes next into the hydraulic main, where it is made to bubble up through a half-inch to an inch of water, and thus some of its vapors are condensed. It then goes to the condenser, a series of iron tubes surrounded by water, to be cooled and more completely rid of its tar and other vapors, which are precipitated and led away. Going to the washers, a series of chambers where it is brought in contact with jets of water, and to the scrubbers, where it passes through a collection of coke, fire-brick, etc., moistened with water, it is relieved of the rest of the tar and also of the ammonia.
The third step in the manufacture is purification, which removes from the gas the noxious elements, chiefly carbonic acid and sulphuretted hydrogen. The first lowers the illuminating power very greatly: one per cent, being sufficient, it is said, to diminish it five per cent. The sulphuretted hydrogen and other sulphurous compounds give rise in burning to sulphurous and sulphuric acids which may injure, by their corrosive action, delicate structures, such as books, gilding, silks, etc., that are exposed to the air of the room in which the gas is burned. Lime and oxide of iron are used in various methods to purify the gas. Lime is used both wet and dry. In the wet-lime process the gas is passed through the milk of lime, which, uniting with the carbonic acid to form a chalk, effectually removes it, and takes, away most of the sulphur compounds too, by uniting with them to form calcic sulphide or calcic sulpho-carbonate.
The use of this process has generally been abandoned, however, ​on account of the foul odor evolved from the lime when it is taken from the purifier. The dry-lime process consists in passing the gas through moistened slacked lime placed upon trays. This is about as effective as the other, and has generally superseded it. The iron process consists in passing the gas through some form of the hydrated sesquioxide of iron mixed with other substances. The great advantage of this process is its economy, it being practicable to use the same mixtures over and over almost indefinitely. The New York Mutual Company, for instance, have used one mixture satisfactorily for three years.
Either petroleum or some of the products of its distillation at a low temperature, as naphtha, rhigolene, gasolene, etc., may be used in the manufacture of gas. These products are of little commercial value as compared with those, like kerosene, which are produced at a higher temperature, but for this reason they are of especial value for the manufacture of gas. The principles on which the manufacture of petroleum-gas depends do not differ much from those involved in the making of coal-gas. In both cases, as already stated, the material is subjected to destructive distillation in a retort; but in this the material may either be introduced directly into the retort, or first converted into a vapor, and conducted into it in that state. The first step, however, is to vaporize the liquid either in the retort or before it reaches there; and the second, to decompose the vapor, and convert it into a fixed gas, which is carried into an hydraulic main and condenser in the same way as coal-gas. One great advantage of the naphtha-gas is that, containing neither sulphur compounds nor ammonia, it needs no purification, and therefore saves one item in the expense of manufacture. Moreover, a loss of some of the luminiferous hydrocarbons is avoided, a certain amount of them being necessarily condensed in the passage through the washers, scrubbers, and purifiers.
The manufacture of water-gas differs entirely from that of coal or naphtha gas. It involves the production, first, of a non-illuminating gas from steam, and, second, of petroleum, naphtha, or cannel gas, to furnish the illuminating power. The great advantage of it is, that very large volumes of non-luminous combustible gas can be made very cheaply. This is done by passing steam over incandescent carbon, which, having a very powerful attraction for oxygen, abstracts it from the steam (water being a compound of hydrogen and oxygen), and unites with it, forming, at first, carbonic acid. This, in passing over another bed of coal, is deprived in turn of one-half its oxygen, and converted into carbonic oxide. Hydrogen, the other constituent of the steam, being set free, mixes with the carbonic oxide. The resultant is a mixture of hydrogen and carbonic oxide, which gases are both combustible but non-illuminating. In some processes for the manufacture of this gas, the petroleum or naphtha gas ​is not mixed with the water-gas until the latter has been purified; in others the petroleum is added directly to the coal. Anthracite coal, only, is used in the manufacture of water-gas, and great care is necessary to keep the temperature up to a white heat, since, if it falls too low, a large proportion of carbonic acid will be formed, and will injure the illuminating power of the gas unless it is removed by purification. Anthracite coal contains sulphur, and yields ammonia when distilled, so that purification is as necessary for water as for coal-gas, and therefore no saving is made in this respect. The real saving is in coal, since a large volume of steam can be decomposed by one ton.
It is necessary now to make a more particular inquiry into the nature of the different gases and compare them with each other. Coal-gas in its salable condition is composed about as follows:
| NAMES. | Heidel- berg. | Bonn. | Chemnitz. | London, Common. | London, Cannel. |
| Hydrogen | 44.00 | 39.80 | 51.29 | 46.00 | 27.70 |
| Marsh-gas | 38.00 | 43.12 | 36.45 | 39.50 | 50.00 |
| Carbonic oxide | 5.73 | 4.66 | 4.45 | 7.50 | 6.80 |
| Olefiant and other hydrocarbons | 7.27 | 4.75 | 4.91 | 3.80 | 13.00 |
| Nitrogen | 4.23 | 4.65 | 1.41 | 0.50 | 0.40 |
| Oxygen | | | 0.41 | | |
| Carbonic anhydride | 0.37 | 3.02 | 1.08 | 0.70 | 0.10 |
| Steam | | | | 2.00 | 2.00 |
The hydrogen and carbonic oxide burn with a non-luminous flame, and marsh-gas burns with only a slightly-luminous one, the illuminating power coming almost entirely from the olefiant gas and other hydrocarbons. The oxygen, carbonic acid, and nitrogen, being incombustible, injure the illuminating power very greatly. The oxygen and nitrogen are admitted accidentally by the introduction of a little air in charging the retorts. Hence, other things being equal the illuminating power of the gas increases with the proportion of olefiant and other hydrocarbons, and these depend chiefly on the kind of coal used and the temperature at which it is carbonized. The gas-coals are the bituminous caking coals and cannel. The bituminous shales, like the boghead mineral of Scotland, and asphalt minerals, like the Albertite of Nova Scotia and the Grahamite of West Virginia, are used in small quantities for enriching. The yield of good gas-coal, like the Penn, is about 10,000 cubic feet of 15 to 16 candle-power gas to the ton (2,240 lbs.). The enriching coals yield a larger amount of richer gas, and the asphalt minerals from 13,000 to 15,000 cubic feet of 30 to 50 candle-power. The relative cost of enriching with these or with naphtha is a very important question. In a number of experiments made at the Boston Gaslight Works, for the purpose of testing the value of Albertite as an enricher, it was found that the ​yield varied from 13,440 to 16,016 cubic feet of 36.08 to 54.45 candlepower gas per ton (6 to 7.15 feet per pound). Experiments on cannel of different kinds have given various yields, from 3.8 feet of 20.52 candle-power gas per pound to 4.74 feet of 30.40 candle-power.
The principal impurities in coal-gas are, as already indicated, sulphuretted hydrogen and other gases containing sulphur and ammonia. The presence of a small amount of these cannot be avoided, and is not injurious, since the sum of the products of the combustion of these substances, formed by the burning of the gas from a single burner during an entire evening, is very small. In fact, the presence of a slight amount of ammonia is beneficial, in tending to neutralize the sulphurous and sulphuric acids formed by that portion of the sulphur which cannot be renewed. The limit prescribed by law for the London companies is 20 grains of sulphur and 212 grains of ammonia per 100 cubic feet. The specific gravity of illuminating gas is an important quality, since it increases in a nearly constant ratio with the candle-power, so that, knowing the one, the other can be told pretty nearly, and vice versa. It varies usually from 0.400 to 0.500; the specific gravity of air, 1.000, being taken for the unit. The denser the gas the more slowly it will pass through a given orifice, and so on this quality depends in great measure the quantity which passes through the consumer's meter and burner.
In regard to petroleum as a gas-making material experiments made by Prof. A. Wagner show that naphtha is better and more economical than it or any of the heavy oils. Fifty kilogrammes of petroleum produced 1,547 cubic feet of gas, while the same amount of naphtha produced 1,619 cubic feet. Both petroleum and naphtha produce a large amount of acetylene, a gas which contains a large proportion of carbon. In the experiments referred to, five per cent, of acetylene was evolved, 35.96 per cent, of other heavy (rich) hydrocarbons, and 59 per cent, of light (poor) hydrocarbon gas; the petroleum being split up, with deposition of carbon, into a mixture of acetylene, heavy and light hydrocarbon gas, and hydrogen. In this country, where petroleum and its products are much cheaper than they are in Europe, it has been found that on a large scale 60 to 80 cubic feet of 50 to 70 candle-power gas can be made from one gallon. In a series of thirteen experiments on crude petroleum made by Mr. C. D. Lamson, of the Boston Gaslight Company, the average yield per gallon was 72.71 cubic feet, and the average of six tests of candle-power was 45.73. In seven experiments on naphtha the average yield was 79 cubic feet, candle-power 53.48. This is equivalent to a yield per barrel respectively of 3,053.82 and 3,338.58 cubic feet. According to Mr. J. D. Patton, about 70 cubic feet of 80 candle gas, or 80 feet of 70 candle gas to the gallon, is the maximum yield of petroleum or naphtha. A much smaller burner than the ordinary must be used for gas obtained from pure Albertite, petroleum, or naphtha; otherwise the flame will smoke, ​and much light be lost, although, on account of their greater specific gravity, less of any of such gases would pass through the same burner in a given time.
Reference has been made to the large quantity of water-gas that is made by one ton of coal. In one of the processes employed, the average result of four months' working was 1,000 cubic feet of gas to 67.71 pounds of coal and 3.22 gallons of crude petroleum, or 33,082 cubic feet of about 19 candle gas to one ton of coal and 106.5 gallons petroleum: allowing 70 cubic feet for each gallon of petroleum, or 7,335 feet for the whole, there remains 25,745 feet for the one ton of coal. It will be remembered that the amount of gas obtained by distillation, from the very best coal, ranged between 10,000 and 16,000 cubic feet. Water-gas contains as a rule 40 to 50 per cent, of hydrogen, 30 to 40 per cent, of carbonic oxide, 10 per cent, of naphtha or petroleum gas, and a few per cent, of carbonic acid. The large proportion of heavy petroleum-gas (sp. gr. 0.600 to 0.700) and carbonic oxide (sp. gr. 0.967) makes its specific gravity much heavier than that of coal gas; but the hydrogen, which is the lightest known gas (sp. gr. 0.067), brings it down to between 0.500 and 0.600.
It has been seen that the gas of common coal is of comparatively poor illuminating power, unless enriched by the gas of other coals or of petroleum, and that water-gas of itself possesses no illuminating power whatever. Although, in considering the nature of the different gases, their relative values were incidentally compared, it is necessary to speak of them now more particularly. In regard to quality, it has been shown that naphtha-gas is the purest, since it contains no sulphur or ammonia, and that it is the richest, being from 60 to 80 candle-power, while common coal-gas is only from 15 to 20 candle-power. It is also the most economical, alike for producer and consumer: for the consumer, because, owing to its higher specific gravity, it burns much more slowly than the coal-gas, while it also gives a better light. The higher the specific gravity of the gas, the longer it will take to pass through a given orifice, and therefore the more slowly it will consume; and the higher the candle-power, the less gas is burned in giving the same amount of light. It is more economical for the producer, because, in the first place, there is a great saving in its manufacture, in the handling of the material. The retorts can be supplied continuously, and the frequent interruptions for recharging necessary, in the use of coal, are avoided. Each retort, too, can be made to produce a much larger amount of gas in the one case than in the other. About 10,000 feet of petroleum-gas can be made daily with a single retort, against about 5,000 feet of coal-gas; and 60,000 to 70,000 cubic feet per day, per stoker, against 25,000 to 30,000. Hence there is a saving both of labor and wear and tear of works. The cost of works for making pure petroleum-gas is also much less than that of coal-gas works. Notwithstanding these facts, the commissioners, whose report we have ​been considering, did not deem it practicable to change at once to the use of pure petroleum or naphtha gas in Boston, as the burners in use are, for reasons already given, not suitable; the works employed to produce coal-gas are not adapted to this, and as the flame of petroleum-gas "burning in an appropriate burner is a very small flame," it would not in their opinion prove satisfactory to consumers, although the amount of light would be the same if not greater. The objection that petroleum-gas in any form injures the metres was found to be without warrant.
The practice which obtains with the Detroit Mutual Company and others, of adding air to naphtha-gas to reduce its illuminating power so that it can be burned in an ordinary burner, was judged by the commissioners to be the reverse of economical, to both the company and consumer, because the deterioration of the gas by this means is in greater ratio than the increase of its volume. It is said that one per cent, of air will reduce the illuminating power six per cent., or more than carbonic acid, the removal of which is considered necessary by all gas-engineers for the sake of economy. It was for this reason that the first attempt to make illuminating gas from petroleum (that at Saratoga by the Gale and Rand process) failed.
What is true of the value of naphtha as a gas-making material used alone, is also true of its value as an enricher. Experiments already here referred to, although not expressed in terms of equality, imply the superiority of naphtha to Albertite, which is about the best of the enriching coals. The yield from a ton of the latter, which costs about $25, was, on the average of a number of experiments made by the Boston Gaslight Company, only 14,694.4 cubic feet of 55 candle gas; while the yield of $25 worth of naphtha (valuing it at ten cents a gallon, which is rather high) would be 19,872.5 cubic feet of 64.5 candle gas, or 5,178.1 cubic feet more gas of richer quality than a ton of Albertite. By the use of naphtha, too, a larger amount of gas is obtained from the ordinary caking coal. In enriching with Albertite the coal with which it is mixed is distilled in an iron retort at a comparatively low temperature; while, if naphtha be used, all of the common coal can be carbonized in a clay retort, which is acknowledged by all to be more economical, and all of the gas in the coal can be exhausted, so that about 1,000 cubic feet more can be obtained per ton. The iron retorts are more expensive than the clay, because their first cost is greater, and they do not last as long. In making gas on a large scale, about one-half the number of retorts can be dispensed with, in the use of naphtha as an enricher. The New York Mutual Gas Company, for example, in this way, make as much gas with forty retorts as can be made in the other with eighty; and with the disuse of the extra forty retorts the labor necessary to tend them is dispensed with. The increased yield of the coal by the use of naphtha, referred to just now, is demonstrated by practical experience to be ​very considerable. Comparison of the result of a year's work obtained by the New York Mutual Company, which uses naphtha for an enricher, and the Boston Gaslight Company, which uses Albertite, shows that the former obtained 10,975 cubic feet of 19 to 20 candle-power gas per ton of coal used, while the latter obtained only 8,779 cubic feet of 18 to 19 candle gas, a difference of 2,196 cubic feet per ton in favor of the naphtha.
In regard to the alleged danger in keeping large quantities of naphtha in store, the commissioners say: "There is no doubt that it is more difficult to extinguish burning naphtha than, burning coal; but the statements that naphtha is like gunpowder (explosive), and dangerous to store, are erroneous. In fact, it is almost impossible to mix naphtha-vapor and air so as to make an explosive mixture, for the reason that, when the proper amount of oxygen is present, the mixture is diluted with so large a bulk of inert nitrogen that it cannot be ignited." In regard to the supply, they see no reason to fear that it will be inadequate to "any demand which may exist in the future." The oil-region extends over a wide expanse of country, embracing large districts in Pennsylvania, Eastern Ohio, West Virginia, Kentucky, Indiana, and Western Canada. The production in 1874 was 10,910,303 barrels—larger than ever before by more than 1,000,000 barrels; the average price was 2.8 cents per gallon, or $1.17 per barrel.
The objections urged against water-gas are, that its specific gravity is too high; that it contains a large proportion of the extremely poisonous gas, carbonic oxide; and that the manufacture, being in its infancy, is not yet proved to be a success. The first is of no importance, since the specific gravity, unless it is caused by the presence of a large amount of carbonic anhydride, is high in almost exact proportion as the illumination power is great.
The commissioners say of the second objection that it is, in their opinion, "sufficient to entirely prevent the use of the mixed hydrogen and carbonic oxide" (unenriched water-gas) "alone for heating purposes, for the reason that, since it is devoid of odor, its escape from pipes and diffusion through the air of an inhabited room, in dangerous amount, could not be detected. The addition to it of petroleum-gas as an enricher, for illuminating purposes, at once imparts to it a peculiar odor, as strong as that of coal-gas, which would lead to the immediate detection of a leak." Carbonic oxide is one of the most active poisons, producing, when inhaled, speedy death. Unlike carbonic acid, which, when it poisons, does so by merely preventing the entrance of air or oxygen into the lungs, as water does in case of drowning, so that persons affected can be readily resuscitated, it is a true physiological poison. And while the first can be rendered harmless by a moderate dilution with atmospheric air, the last produces death almost as readily when diluted as when pure. It forms a ​compound with the red coloring-matter of the blood, which is more stable than that formed by carbonic anhydride, and cannot be readily decomposed by oxygen. According to Leblanc, one volume of it diffused through one hundred volumes of air totally unfits it to sustain life; and it appears that the lamentable accidents which too frequently occur from burning charcoal or coke, in braziers and chafing dishes, in close rooms, result from the poisonous effects of the small amount of carbonic oxide which is produced and escapes combustion, since the quantity of carbonic anhydride thus diffused through the air is not sufficient in many cases to account for the fatal result. The commissioners, therefore, do not consider the use of water-gas as safe as that of coal or naphtha gas, but they say that the addition to it of petroleum-gas greatly diminishes the danger. So far as they are aware, no accidents have occurred from its use in this country, although there have been several in Europe. The third objection, that the manufacture of water-gas is yet in its infancy, is to a certain extent true, as, although it has been in use in Utica, New York, where the works were recently burned, and is in use in one or two small places, as Poughkeepsie, New York, and the Manayunk District of Philadelphia, it has not been adopted by any of the large companies of Europe or America.
By a comparison of the results obtained by the leading companies in this country and Europe, some interesting facts are shown concerning the cost of production, which, in the United States, has been shrouded until now in mystery—the value of the different processes, the prices charged, etc. The accounts of the London companies, and of the companies of several other large European cities, are published, and therefore open to examination; but, with one or two exceptions, notably of the Philadelphia works, which are controlled by the city, this is not the case with American companies, which are, on the contrary, careful in guarding the secrets of their business. From most of them, certain items of information could be obtained by the commissioners only under the promise of secrecy. The prices charged consumers in Europe are generally much lower than those charged in this country, and it seems that, owing to cheaper labor and better prices obtained for the residuals (coke, tar, and ammoniacal liquor), the cost of manufacture is considerably less. The average price varies with companies and places, from $0,827 per 1,000 cubic feet at London to $1.51 at Paris. The lower price given, however, is charged by only one London company, the S. Metropolitan; the prices of the other companies are much higher, varying from $1.09 to $1,367. The lowest cost of production, 59 cents per 1,000 feet, is reached by the London company just named, and the highest, $1.21, by the Hamburg company. The high cost in Hamburg is to be partly accounted for by the fact that the price of labor is higher there than in any other European city. In 1875 the lowest price in any of the large cities ​of this country was in Philadelphia—$2.30. In Boston the price was $2.50, and in New York $2.75; these prices were, however, reduced, in the early part of 1876, to $2.25 and $2.50, respectively. The prices charged in the smaller cities are, as a rule, much higher, being in some cases—Ashland and Bloomsburg, Pennsylvania, for example—as high as $10 per 1,000. In Detroit, Michigan, owing to a temporary war between an old and a new company, the price was as low as 50 cents per 1,000 in one part of the city, and $1 in another; while in a third, supplied only by the pipes of the old company, it was $3.
With regard to the Philadelphia company, which, as before stated, is under control of the municipal authorities, it was found that, while the price charged was the lowest, the cost of the gas was the highest. It had been alleged that the authorities were in the habit of giving employment to laborers for political purposes about election-time, and it was found that the cost of labor was ten cents per 1,000 feet greater than in other works. The proportion of capital to business done varies very greatly with different companies. In Washington, D. C, it was $1.46 per 1,000 cubic feet of gas sold, and in Brookline, Massachusetts, $17.50. "This," remark the commissioners, "must be due, to a great extent, to improper investments or expenditures, and is the great argument against any monopoly being in the hands of a private corporation, and in favor of its management by municipal authorities, since a corporation, having a monopoly, has the power to charge such a price as may be necessary to pay its dividends, and has, therefore, no inducement to diminish its capital, but, on the contrary, one to increase it." The average capital and borrowed money of the London companies, in 1874, was $4.54 per 1,000 cubic feet of gas sold.
As information given them touching the net cost of manufacture was confidential, the commissioners were deterred from publishing the facts as they found them, and forced to resort to giving an approximation. For this purpose, they compare the New York Mutual Company and the Boston Gaslight Company, as being more nearly on an equality, with respect to business done and capital employed, than any others, and deduct the "amount of dividends and taxes pro rata per 1,000 cubic feet sold from the average price of gas to the consumer." Each of these companies has an actual paid-in capital of $2,500,000, and bonds to the amount of $500,000. The first paid, in 1875, twenty per cent, dividends on the capital, six per cent, interest on the bonds, and $50,000 taxes, making, in all, $580,000, which, divided among 509,000,000 cubic feet of gas sold, gives $1.14 for each 1,000 feet; this amount, deducted from the net price per 1,000 feet, $2.65, leaves $1.51, which is supposed to be the cost of the gas; and that, the commissioners assure us, is even more than the actual cost. In the same manner the cost of the Boston gas is ascertained to be $1.85 per 1,000 feet, or thirty-four cents more. This difference is ​partly due to the use of Albertite instead of naphtha as an enricher, which, as already shown, is more expensive, and partly to greater cost of common coal, labor, and distribution, and smaller receipts for residuals. The leakage, for instance, is only seven per cent, with the New York Mutual, while it is eight and one-half per cent, with the Boston company. The commissioners, however, believe that the gas of this company ought not to cost the consumers more than $2 or $2.10 per 1,000 cubic feet.
Examination of the gas of the New York Mutual showed it to be very pure, and of a high illuminating power. It contained of ammonia about one-quarter of a grain in 100 cubic feet, and less than nine grains of sulphur. Its specific gravity averaged 0.729, and its illuminating power between 20 and 21 candles. The London companies, as before stated, are prohibited by law from allowing the amount of ammonia in each 100 feet to exceed two and one-half grains, and of sulphur twenty grains, and from permitting the candlepower to fall below 16. The amount of ammonia in the Philadelphia gas was found to be 52 grains per 100 cubic feet. "The candle-power," say the commissioners, "is always within the control of the company, and it ought in no case to be allowed to fall below the London standard." In regard to the charges of smokiness made against the gas of the New York Mutual Company, the commissioners, after a thorough investigation, ascertained that where smoke occurred it was due to the ignorance or carelessness of consumers in using unsuitable burners.
All the principal water-gas works were visited, and found to be producing gas of good quality. The cost by the Harkness process, used at New London, Connecticut, exclusive of the cost of labor, purifying, and fuel for the petroleum-retort, which, by this process, requires a separate fire, was found to be about 75 cents per 1,200 feet. The Lowe process, in use in Utica until the works were burned, requires but one fire for decomposing both steam and petroleum, so that it possesses an advantage over the other in regard to the cost of production. The friends of this process claim that, manufacturing at the rate of 200,000 cubic feet per day, the gas can be made (coal being at seven dollars a ton, and petroleum at twelve and one-half cents a gallon) at a cost of 53 cents per 1,000 feet, exclusive of labor, fuel, and purifying. For the Gwynne-Harris process, in use at Poughkeepsie, New York, it is claimed that the cost, under like conditions, is only 37.3 cents per 1,000 feet.
The relation of a gas company to a municipality, the commissioners say, is a peculiar one in many respects, and the company ought not, therefore, to be viewed in the same light with other manufacturing corporations. It supplies a commodity which is not a luxury but a necessity; the sale of its product is a limited one, being confined to the city or district which it supplies; and it is expected to lay its ​pipes so that all who desire to burn gas may do so, which entails an expenditure in distribution that is not, perhaps, repaid by the sale of gas in the particular locality for many years; and a very large part of its first investment is in material that would not give any return in case it became bankrupt, or desirous of withdrawing from the business. Therefore it is entitled to a great deal of consideration, provided it performs "its duty to its customers, and is honorable in all its transactions." A general view is then taken of the London companies, the result of their competition, and the efforts which have been made to control them by parliamentary enactments. In the efforts that were made from time to time, between 1820 and 1857, to reduce the price of gas, a number of new companies were chartered and established, until at length thirteen existed, and in some of the streets the mains of three or four companies lay almost in contact with each other. When a leak occurred it was impossible to tell from which main the gas escaped—it was, in some places, impossible to tell with certainty to what company a particular main belonged, and it sometimes happened that a consumer would use the gas of one company and pay for it to another. These circumstances, of course, did not tend to lessen the cost of gas, and so the companies finally agreed to district the city off and abandon competition. Then followed a consolidation of five companies with others, so that only eight remained, and latterly three of these consolidated into one, whereby the number is reduced to six—which result, corresponding as it does with the history of gas companies elsewhere, proves that competition does not operate to reduce the price of gas. It only illustrates the truth of the remark made by John Stuart Mill, and accepted by other political economists, that "where the competitors are so few (as in the case of gas companies), they always end by agreeing not to compete. They may run a race of cheapness to ruin a new candidate, but as soon as he has established his footing they come to terms with him." It eventually ends by the public having to pay the profits on two or more capitals instead of one.
As early as 1820 a committee of Parliament, of which Sir William Congreve was chairman, reported in favor of granting a monopoly under certain restrictions to each company in its own district; but the recommendation was not adopted. As the matter now stands the companies are restricted by law from charging more than 3s. 9d. per 1,000 cubic feet, and from paying more than ten per cent, dividends on stocks. The law also compels the companies to submit their accounts to the inspection of an auditor, at his pleasure; to publish annual statements of the cost of manufacture, profits, etc.; and it empowers the local municipal authorities to erect works and supply gas if the companies will not agree to sell gas for 3s. 9d.; and the same authorities may, if they think that ten per cent. dividends can be paid at a less price ​than 3s. 9d., call for the appointment of three commissioners to reduce the price. And a company may call for a like commission to raise the price if 3s. 9d. will not pay its allotted dividend.
With regard to the manufacture of gas by municipalities, the commissioners say that the best argument in its favor is, that about fifty cents per 1,000 feet of the gas sold must be applied to the payment of dividends to stockholders, while "a much smaller amount than this, at the low rate at which money could be hired by the city, would be sufficient to pay interest on the capital, and at the same time allow a sufficient amount to be laid aside, in the form of a sinking-fund, to entirely liquidate the debt in a few years." However, "as a rule a city cannot manufacture gas as cheaply as a private corporation, since it is almost impossible to avoid the influence of politics on any city undertaking." Concerning the Philadelphia works, which is the most notable example of municipal manufacture in this country, the commissioners speak as follows: "Notwithstanding all the disadvantages arising from political influence in the management of these works, we find the profits for the year 1875 to have been $793,244.12; and after deducting for interest on the bonds, etc., the sum of $302,986.21 went toward the increase of the sinking-fund, which, on December 31, 1875, amounted to $2,470,193.93, while the whole amount of outstanding bonds is $5,400,000; thus leaving only $2,929,806.07 to be provided for, when the whole works, costing nearly $14,000,000, will become the unencumbered property of the city."
The conclusions arrived at by the committee may be summarized as follows: That although Boston is supplied with gas of excellent quality, at a lower price than most other cities of the United States, the same could be made much cheaper than it is, by the use of naphtha or petroleum as an enricher, but it is doubtful whether the appliances for using that substance could be employed by the Boston company without paying a considerable royalty, or becoming involved in lawsuits for alleged infringement of patents, which are, however, of doubtful validity; that the "Gwynne-Harris" and "Lowe" water-gas processes offer fair prospects of success, and should be carefully watched and studied; that the existing companies in Boston, and other cities in Massachusetts, should be granted monopolies in their several districts, subject, however, to the supervision of a permanent Board of State Commissioners, similar to the Railroad Commissioners, and to a full annual publication of their entire business, and be required to keep their gas at all times up to an illuminating power of sixteen candles, free from sulphuretted hydrogen, and from more than twenty grains of sulphur and five of ammonia, per 100 cubic feet; and, finally, that the authorities of the city of Boston should be empowered by the Legislature to erect works and manufacture and supply gas to the citizens in case any company which, by the terms of its charter, is not subject to ​legislative control, should refuse to comply with such reasonable suggestions as may be deemed necessary to insure publicity in regard to its business, proper inspection of its gas, and a limitation of its earnings.