LIBRARY OF THE UNIVERSITY OF CALIFORNIA. Class THE AMERICAN PRACTICE OF GAS PIPING AND GAS LIGHTING IN BUILDINGS THE AMERICAN PRACTICE OF GAS PIPING AND GAS LIGHTING IN BUILDINGS BY WM. PAUL GERHARD, C.E. CONSULTING ENGINEER TOR HYDRAULIC AND SANITARY WORKS, MEMBER AMERICAN SOCIETY MECHANICAL ENGINEERS, AMERICAN PUBLIC HEALTH ASSOCIATION, ETC., CORRESPONDING MEMBER AMERICAN INSTITUTE OF ARCHITECTS. ETC. Published by the McGraw-Hill Book. Company to the Book Departments of the McGraw Publishing Company Hill Publishing" Company Publishers of Books for Electrical World The Eno^neering and Mining Journal The Engineering Record Power and The Engineer Electric Railway Journal American Machinist II11I11UJ- THE AMERICAN PRACTICE OF GAS PIPING AND GAS LIGHTING IN BUILDINGS BY WM. PAUL GERHARD, C.E. CONSULTING ENGINEER FOR HYDRAULIC AND SANITARY WORKS, MEMBER AMERICAN SOCIETY MECHANICAL ENGINEERS, AMERICAN PUBLIC HEALTH ASSOCIATION, ETC., CORRESPONDING MEMBER AMERICAN INSTITUTE OF ARCHITECTS, ETC. UNIVERSITY NEW YORK McGRAW PUBLISHING COMPANY 1908 COPYKIGHTED, 1908, BY THE MCGKAW PUBLISHING COMPANY NEW YORK PEEFACE IN preparing this book my object was not to treat of the various processes of manufacture and distribution of illuminat- ing gas, nor to discuss the lighting of public streets, alleys, parks and squares. It should be distinctly understood by the reader that I take up the subject of gas installation and gas utilization practi- cally at the point where it reaches the consumers 7 premises. I endeavor to explain how gas-fitting should be done so that gas may be advantageously employed in the illumination of the interior of buildings. Incidentally, other uses of gas are mentioned and their advantages pointed out. To give a detailed technical instruction regarding the practical work and the mechanical details of the gas-fitter's work in the piping of buildings was beyond the scope of the book. Several smaller handbooks, mentioned in the bibliography, are avail- able, which cover the ground fairly. In compiling the bibli- ography (Chap. XXVII) the author arranged the literature, as far as dates were available, by the year of publication. The book is intended chiefly for the use and enlightenment of the gas consumer and the householder. However, it will also be found useful by architects, engineers, builders, and building superintendents to enable them to acquire a better knowledge as to how to introduce, distribute, and utilize gas in buildings. It should also be of value and interest to gas companies and superintendents of gas distribution service. The author is under many obligations to Mr. Otis Allen Kenyon, M.E., for valuable suggestions, as well as for his criti- cal revision of the manuscript. He also desires to acknowledge assistance received from Norman P. Gerhard in preparing the bibliography, from Hans W. Gerhard in making the alphabetical index, and from Mr. R. N. Hart in careful proofreading. THE AUTHOR. NEW YORK CITY, January, 1908. 202027 CONTENTS PAGE PREFACE I. PREJUDICES AGAINST THE USE OF GAS 1 N II. POPULAR FALLACIES ABOUT GAS 8 III. ADVANTAGES OF GAS AS AN ILLUMINANT 12 IV. ADVANTAGES OF GAS AS A SOURCE OF HEAT AND POWER 16 V. THE ARRANGEMENT OF GAS PIPING IN BUILDINGS ... 22 VI. SPECIFICATION FOR GAS PIPING FOR COAL OR WATER "*" GAS 41 VII. RULES, TABLES AND REGULATIONS OF GAS COMPANIES AND OF BUILDING DEPARTMENTS 44 VIII. PIPING FOR NATURAL GAS 81 IX. PIPING 'FOR AIR GAS OR GASOLINE MACHINE GAS ... 87 X. PIPING FOR ACETYLENE GAS 97 ^ XI. THE TESTING OF GAS PIPES . - 102 XII. GAS-LIGHT ILLUMINATION 108V- XIII. GAS BURNERS Ill Y XIV. GAS-PRESSURE REGULATION 126 XV. GAS GLOBES AND GLOBE HOLDERS 137 XVI. GAS FIXTURES 142y GAS METERS AND GAS-METER STORIES 148 THE ILLUMINATION OF INTERIORS WITH GAS LIGHTS . . 170 XIX. THE LIGHTING OF COUNTRY HOUSES 179x , XX. THE RELATIONS BETWEEN GAS COMPANIES AND GAS CONSUMERS 198 . XXI. PRACTICAL HINTS FOR GAS CONSUMERS 207 . XXII. SOME FACTS ABOUT THE GAS SUPPLY 222 XXIIIT ACCIDENTS WITH GAS 229 XXFV/ DANGERS TO THE PUBLIC HEALTH FROM ILLUMINATING AND FUEL GAS 237 XXV.*" DANGERS OF GAS LEAKAGE (continued) 256 XXVI. HISTORICAL NOTES ON THE DEVELOPMENT AND PROGRESS OF THE GAS INDUSTRY 263, XXVII. BIBLIOGRAPHY OF GAS LIGHTING 279 - ALPHABETICAL INDEX 295 OF THE UNIVERSITY OF THE AMEEICAN PKACTICE OF GAS PIPING AND GAS LIGHTING IN BUILDINGS CHAPTER I. PREJUDICES AGAINST THE USE OF GAS. IN the following pages the term "gas" is used to designate an aeriform mixture, used either as an illuminant or as a fuel. When used for lighting, gas is called illuminating or lighting gas, and when used for heating, cooking, or power purposes it is called fuel gas. Gas used for illumination is largely hydrogen enriched by carbon. We also distinguish between natural or rock gas and artificial or manufactured gas, the former being found hi nature beneath the earth's surface and brought up by means of bored wells, the latter being gas manufactured in industrial establishments or gas works, or in special private gas plants or apparatus. The bulk of manufactured illuminating gas is either coal gas, the product of the distillation of bituminous coal in closed retorts, to which a high degree of heat is applied, or else it is water gas, made more cheaply than coal gas by passing steam over glowing coals, and afterwards enriching it with vapors of oil or naphtha to make it luminous. Very little oil gas is made from hydro- carbon oils. Water gas has considerably less heating power than coal gas, but in all other respects both kinds of gas, sup- plied from a central station through a system of distributing pipes, and brought by service pipes into the houses of the con- sumers, are well adapted for light, heat and power. Air gas is a special gas, used to a limited extent in the lighting of country houses, and made by forcing common air to pass over gasoline or other fluid hydrocarbons, the air becoming saturated with the vapors of the fluid* Acetylene gas is another special gas discovered, more recently, and obtained by the contact of calcium carbide with water.. 1 ! 2 Gas Piping and Gas Lighting Sometimes the term "gas" is used to designate a gas lamp, a gas jet or a gas burner, or the light produced by burning gas. A rather unusual, but witty, definition of "gas" is the follow- ing, which I quote from the "Silly Cyclopaedia": a gas a sub- stance we make light of until the bill comes in." The industry of manufacturing illuminating and fuel gas celebrated the anniversary of its first century in 1892, for it was in 1792 that Thomas Murdock, in England, first illuminated his house with gas. Although the advent of the electric incandescent lamp, in 1880, threatened at first to revolutionize completely the methods of both interior and street illumination, the gas-lighting industry has continued to flourish and to show during the past 25 years an ever-increasing consumption of gas for lighting, heating and power purposes. The growth has been particularly noticeable in the so-called "day consumption" of gas, it 'being at present used to a large extent in gas heating and gas cooking appliances, and also for power purposes, in gas motors and engines. Notwithstanding the numerous improvements, introduced in gas appliances and in gas illuminants, there are still found, in certain quarters, ill-conceived and old-fashioned prejudices in opposition to the use of gas, and it is with a view of doing away with these, and of clearing up misconceptions and exaggerated or erroneous statements that this brief chapter is introduced. The many popular fallacies regarding gas and its uses will be taken up and discussed in Chapter II. We have become so accustomed to the benefits derived from the introduction and use of gas in our dwellings, and from the not less important advantages due to the lighting of our streets, squares, and parks with gas or electricity, that we can scarcely believe it possible that a newspaper should have appeared in Germany in the year 1819, in which the following, to say the least, ludicrous, objections against street lighting were brought forth. The writer of the article denounced the artificial illumination of streets after sunset because "God had decreed that darkness should follow light, and mortals had no right to turn night into day." He declared that people did not require any light at night outside of their houses, and argued that the lighting of street lamps imposed an unnecessary tax upon the people. He also claimed that the fumes of oil lamps or of gas poison the air ( !) Prejudices against the Use of Gas 3 and affect the health of delicate persons, while public lighting encourages healthy persons to stay out of doors after dark and thereby to catch cold. Street lighting, in his judgment, would lower the standard of morality and remove the fear of darkness which alone prevents weak-minded individuals from committing crimes. The lighting of streets would make robbers bold and cause horses to shy (!). It would also reduce patriotism as evinced in special night illumination during public festivals, because if streets w r ere lighted every night, these special functions would lose their effect. We can, possibly, pardon a man for foolishly decrying in the above words a new industry, at a time when it was first being introduced. But what shall we say of people who, at the be- ginning of the twentieth century, still adhere to notions like the, following : \1 " Illuminating gas is poisonous, and hence dangerous to use; it is explosive and thereby becomes the cause of fires; the com- bustion of gas produces irritating and unhealthy vapors ; " or of those who cry out that "gas is too expensive to use," or those who do not care to introduce gas " because it will soon be super- seded, anyhow, by electricity?" It may not be amiss to take up briefly some of the prejudices mentioned, in order to analyse them and to point out why the statements made are erroneous and misleading. There are some persons who claim that very soon electric lighting will supersede gas entirely, and who, for this reason, are opposed to the introduction of gas into buildings, at least for illuminating purposes. Persons who argue in this way are entirely unfamiliar with the true facts, which they could easily establish by a diligent research, namely, that since the intro- duction of electric lighting the use of gas has made rapid strides forward. Nearly all gas works show a large increase in gas con- sumption, and many instances are named where electric incan- descent lamps have been replaced by the improved forms of incandescent gas lamps. Even in the lighting of railroad cars, no progress has been made in recent years in the use of electric lamps, whereas, only recently, successful experiments were made in lighting passenger cars with the Pintsch gas, burned in neat- looking, inverted, incandescent mantle burners. Many other facts could be cited to show that there are no indications whatever that electricity will replace gas entirely. 4 Gas Piping and Gas Lighting A number of important inventions in the gas industry are re- corded each year, and the old question : electricity or gas ? is no longer of importance, for both forms of lighting have their merits, advantages and uses in special cases, and there is certainly room for further improvements in both fields of illumination. Contrary to recent opinions held by some architects, the author can give no better advice to those who are building resi- dences, than to have their houses both piped for gas and wired for electricity. Many instances are on record where the electric lighting has failed temporarily, for local reasons, or because the electric lighting plant or works were, for a time, put out of commission. It is at such times that the fact that gas is avail- able will be most appreciated. There are a number of other persons who have no real objection to the use of gas, but who fondly maintain the notion that "gas is an expensive luxury." There was a time when gas did cost more than other materials for illumination, such as oil or kerosene, but that time has long gone by, and the price of gas has gradually come down, so much so that at the present time residents in many cities are charged less than one dollar per thousand cubic feet of gas consumed. It is true that gas is a luxury, if burned in wasteful burner tips; and it is also a fact that many persons using gas in their cooking ranges have large gas bills, because the cook is indifferent as regards turning off the gas the moment it is no longer wanted. But such objections cannot be considered valid, because they can be overcome by the use of a little care or judgment and by proper instruction. On the other hand, it is a well-known fact that consumers can obtain for less money than formerly a very much higher degree of illumination, as, for instance, by using the modern forms of incandescent gas burners, all of which are much more economical in gas consumption than the flat-flame burners. Others again are afraid to use gas for illumination or other purposes because "the products of combustion of gas are un- healthy." The chief products of combustion of illuminating gas, whether coal oi 4 water gas, are carbonic acid and water vapor. If gas is properly purified at the works and burned in the houses under proper conditions, only a trifling amount of deleterious compounds escapes into the air of the rooms. The objection raised can certainly not be restricted to gas illumination, for it is well known that other forms of illumiriants, Prejudices against the Use of. Gas 5 such as kerosene or oil lamps and candles, contaminate the air to an even greater extent. Where many people congregate to- gether, as in theaters or other halls of assembly, the air is polluted much more by the products of respiration and by exudations from the skin than by the lighting flames. Proper and sufficient ventilation should, of course, be provided in all cases, and it may be said that while the electric light doubtless exercises a less deteriorating influence on the air of closed rooms, the gas flames, on the other hand, assist in their natural ventilation. Scientific authorities and noted hygienists seem to agree that one has little to fear from the use of gas for illumination, and the fact is worth pointing out that the improved burners, like the Welsbach incandescent and others, create a very much smaller amount of pollution, by reason of the fact that they burn less gas for a same amount of illumination than the large flat- flame burners. Still other people, who do not deny that gas offers many ad- vantages, entertain and cling to the prejudice that "illuminating gas is dangerous to life because it is poisonous." But when gas is introduced into dwellings it is conveyed in tightly jointed pipes and fixtures. Both piping and fixtures can and should be made perfectly gas-tight. No doubt this is not always the case, and leaks frequently exist, due to carelessness and indifference. But granting that escapes and leakage of gas are possible, the remedy is a simple one and easily applied. Gas only becomes dangerous to life when it escapes unburned, and in most cases gas leaks are readily noticeable, owing to the odor of the gas. There is somewhat more danger where water gas is distributed to the consumer, owing to its much higher per- centage of carbon monoxide, yet statistics in countries where coal stoves are much used show that more deaths by asphyxia- tion occur through defective stoves, or by the wrong use of the damper in the stove flue, than from gas leaks. A German writer points out that many poisons are used without hesitation in workshops or industrial establishments, and even in the household, also that many of our articles of daily food contain poison, also that carbonic oxide is generated in considerable quantity in tobacco smoking, yet nobody would think of giving up on that account the things which contribute to our comfort. Many deaths from electricity occur, owing to accidental contact with apparatus or wiring carrying a high voltage, yet this 6 Gas^ Piping and Gas Lighting fact is never cited as a valid objection against the use of electricity. The danger from gas leakage and the proper precautions and remedies to be applied will be discussed in later chapters, and it may suffice here to reiterate the statement that the objection quoted is not an important one, and certainly should not deter people from using gas in the household. The last objection to gas to be mentioned comes from persons who claim that it is " explosive," and frequently causes fires. As a matter of fact, coal gas only becomes explosive when mixed with air in a proportion of not less than 4, nor more than 13, parts of air to one of gas. As a rule, accidental escapes of gas are noticed long before the mixture of air and gas become 'explosive. Then, again, gas requires air in order to burn, and when a gas jet is lit the gas burns only at the point where it issues and not in the pipes. A large gasometer, rilled with gas, might be struck by lightning, yet, unless it be rent open to permit the gas to escape and then to become lighted, nothing serious would happen. The danger from fire, incident to the use of gas, is no greater than that attaching to the use of other illuminants with open flames. In fact, reliable fire statistics confirm the view that more fires or explosions are due to the use of petroleum or alcohol lamps than to gas. In a recent number of Cassier's Magazine, Mr. Washington Devereux, inspector for the Philadelphia Fire Underwriters' Association, writing on "Fire Hazards and how to Avoid Them," relates that the Grocers' Exchange of London, England, "has offered a prize of 120 sterling, which for the last three years has gone begging. It is to go to the inventor of the best-con- structed safety lamp in which mineral oil can be burned, the chief merit of which must be absolute safety. The reason for this prize offer is the fact that the number of accidents resulting from the upsetting of mineral oil lamps in the United Kingdom has been enormous, and thousands of deaths have been caused by such accidents. In London alone, there were, in 1901, three thousand accidents, more or less serious, due to defective mineral- oil-burning lamps, stoves and lanterns." The use of gas is not in any way extra hazardous, and the notion that electric lighting is very much safer in this respect is erroneous. Many fire insurance companies, on the contrary, Prejudices against the Use of Gas 7 regard the use of gas as safer than that of electricity. Some underwriters hold the view that no rebates or reductions should be given on policies for buildings illuminated by electricity, and that the relative danger to property and life is not less with electricity than with gas. As an example, I quote the following enumeration of fatal accidents which took place in Germany in 1905: gas explosions killed 9 persons; electricity killed 15 persons; explosions of kerosene lamps, 250 persons. In this connection it might be mentioned that in five years (from 1900 to 1905) not less than 21 fires occurred in Berlin theaters, out of a total of 66 fires, which were caused by short- circuits in the electric wiring installation; hence there seems to be some reason for doubting the greater safety of theaters, in which gas lighting is excluded by building department regula- tions. While these remarks are not intended to undervalue the dangers incidental to the use of gas as an illuminant, they are given to point out the fact, that illuminating gas is not extra hazardous, if proper care and judgment are used in its manage- ment. CHAPTER II. POPULAR FALLACIES ABOUT GAS. HAVING in the preceding chapter referred to some of the common prejudices against gas lighting and the use of gas in buildings, I will now mention a few of the popular misconcep- tions, which seem to arise largely from ignorance or want of knowledge. Among the more common fallacies are the following : a. That gas companies mix air with the gas to increase its volume. This admixture of air is never attempted, because it would obviously result in a serious deterioration of the illuminat- ing power of gas, for even a 1 per cent admixture of air reduces the candle-power of gas by 6 per cent, and a 10 per cent admix- ture reduces the same by 67 per cent. Gas companies are re- quired by law to make and furnish illuminating gas of a specific candle-power, and the weekly tests of the gas examiners show that the quality of the gas rarely falls below this standard, as it certainly would if air were mixed with the gas. It is a fact, however, not so well known, that the quality of gas is variable with atmospheric changes. For instance, a fall in the barometer reduces the brilliancy of lighting by 5 per cent for every inch of fall. According to Dr. Lethe by, "in London the difference in the value of the light when the barometer is 31 inches as com- pared with what it is at 28 inches is fully 25 per cent, and this, no doubt, accounts for many of the complaints of 'bad light ' in November, when the barometer is usually very low." The quality of the light is likewise said to be variable with the amount of moisture in the air. f 6. That gas companies blow or pump air from the works into the gas mains during the day, to make the meter go around and to make the index register. This is sheer nonsense, for not only can the consumer at any time by lighting a burner convince him- self that the pipes contain illuminating gas and not air, but where no gas is burnt and the house pipes are tight, the consumer, by 8 Popular Fallacies about Gas 9 watching the small hand of the meter during the day, will find that it remains stationary. c. That large gas meters lead to an increase in the gas bills, and that large gas pipes in houses, as advocated by gas engi- neers, increase the consumption, and therefore the monthly gas bills, both of which beliefs, of course, are erroneous, as the gas consumption depends only upon the number and size of burners in use, and upon the gas pressure, but not upon the size of the conduit or pipe conveying the gas to the burner, and not upon the capacity of the instrument measuring the gas. No one having large pipes and a large gas meter in his house need burn more gas than he wishes to, and he can control this gas con- sumption perfectly. d. That the gas company willfully puts on more pressure at the works at night in order to make the gas meters in the con- sumers' dwellings go around faster. While the fact is true that the pressure is increased in the early part of the evening, .when a general lighting up begins, the gas company is obliged to do this to supply the distant consumers and those located in low-level districts. The increased pressure causes increased leakage of gas at the joints of the street mains, and also leads to increased consumption at the street lamps with ungoverned burners, for which the companies, as a rule, receive a fixed annual sum by the municipality, hence it may be accepted without question that the gas companies would not increase the pressure if it were not quite necessary to do so. e. That large burners lead to a waste of gas, and that where gas companies offer to put better, or larger burners on the fixtures of the consumer they do this, not for the sake of giving a better light, but in order to increase the gas consumption. Careful observation shows that one large burner gives, with less con- sumption of gas, a better light than two small ones, which demonstrates the fallacy of the above misconception. /. That gas vitiates the atmosphere more and creates more heat than either candles or oil lamps, whereas for the same amount of illumination the opposite is true. g. That gas is more dangerous as regards accidents, such as fire, explosions, escape or leaks of gas causing asphyxia, than other illuminants, whereas the statistics of fire underwriters and the records of hospitals show more fires and accidents caused by lamp explosions than by gas. 10 Gas Piping and Gas Lighting h. That if in one house, owing, perhaps, to insufficient size of the gas service or of the house pipes, the pressure is low and the light accordingly poor, the gas company should be able to remedy this by giving to this consumer more pressure, if he desires it, than to the neighboring houses, which is obviously impossible. i. That gas pipes may burst from the inside gas pressure, which mistaken idea possibly arose at the time when natural gas was first supplied to towns under sometimes very heavy pressure. With gas as supplied and distributed from gas works, the pressure is, comparatively speaking, very low, fluctuating from 10/10 to 40/10 inch of water pressure,* and there is not the slightest reason for fearing that the gas pipes may burst. k. That inasmuch as the manufactured gas emits a strong and unpleasant odor, the same odor must exist and become dissemi- nated in the rooms, when gas is burning. It is a fact, however, sufficiently well established by experience, that properly purified gas, if properly burnt, gives off no obnoxious odors. I. That gas may, and sometimes does, burn inside of the gas pipes. I have met well educated and otherwise intelligent people, who displayed their utter ignorance on the subject by making such statements, thus reminding me of the people, in the early days of gas lighting, of whom we are told that they put on gloves before touching the gas pipes, and of architects who re- quired in their specifications "gas pipes, to be carried at a safe distance from all woodwork." The fact is, of course, that illumi- nating gas does not burn while confined in a vessel or in pipes and fittings conveying the same, because air is necessary in all cases for combustion to take place. m. That manufacturers of gas meters and gas companies work hand in hand to defraud the consumer, whereas the fact is that gas meters are measuring machines constructed with accuracy and on scientific principles, by responsible manufac- turers, and that before use all meters are tested as to their accuracy by special State meter inspectors. Therefore, when- ever a consumer believes his meter to be wrong, he may have it tested, exchanged, or repaired by notifying the gas company. n. That gas bills are made out regardless of the amount of gas * Gas pressure is always expressed in tenths of inches of water pressure. W. P. G. Popular Fallacies about Gas 11 consumed, which popular error has been already alluded to hi speaking of the prejudices of consumers. o. A popular fallacy, which is met with occasionally, is that the gas, after once having flowed through, and been registered on the index of the consumers' meter, may pass back into the street supply pipes, so that gas companies will benefit by a second registration of the same volume of gas. A slight study of the construction of the gas meter (see Chapter XVII) will show the impossibility of this happening. p. Another erroneous impression, which quite frequently pre- vails among gas consumers, is that if the size of the gas pipes is made larger than is common in most houses, there will neces- sarily be an excessive pressure and a correspondingly increased gas consumption. Practically, however, the reverse is the case, for a higher pressure is required to supply the gas burners or the gas cooking ranges with sufficient gas where the pipes are made very small; and, on the other hand, the pressure can be more readily regulated by the consumer, where the gas pipes are of a good size. Much can, doubtless, be done to remove these and similar popular fallacies by giving to gas consumers proper explanations. The gas companies have constant opportunities to give to their customers information and advice upon many of the matters touched upon in this chapter, and it is to their interest to avail themselves of them. CHAPTER III. ADVANTAGES OF GAS AS AN ILLUMINANT. IN this chapter, I shall consider only the many advantages of gas as a source of light, leaving the consideration of the use of gaseous fuel, as compared with liquid and solid fuel materials, for heat and power, for the next chapter. To some it may seem superfluous, at this day, to dwell upon the advantages of gas lighting as compared with other illuminants, and particularly so when it must be admitted that electric lighting is, in some important respects, superior. Electric energy, however, is as yet far from being a cheap source of illumination; it certainly cannot be looked upon as a source of light adapted to the means of the bulk of the general public, and it must be said that, notwithstanding many recent improve- ments, electric lighting is still far from perfection. In the regu- lation of the intensity of the flame, for instance, the gas has the advantage over the electricity in that it can be readily adjusted, regulated, increased or diminished at the will of the consumer. If we except one special form of electric incandescent lamp (the "Hylo" lamp), not universally used, this regulation cannot be accomplished in electric lighting.* But, leaving out of consideration the electric lamp, let us see what chief advantages gas lighting offers. The gaseous form of the illuminant involves some important advantages not possessed by liquid or solid illuminants. Thus, gas is readily conducted in pipes to any place where it is to be used as a source of light. It becomes available in an almost unlimited quantity, this being restricted merely by the size of the service pipe. From the service it is easily distributed to as many different places or outlets as wanted, and its flow is conveniently regulated. There are other important considerations of convenience where gas is used, such as the avoidance of loss of time, the * Since writing the above, another device has been introduced, the object of which is the regulation of the light intensity of incandescent lamps. W. P. G. 12 Advantages of Gas as an Illuminant 13 labor or annoyance of purchasing and getting the materials required for illumination, the candles or the kerosene oil and the lamp wicks; nor is any trimming and cleaning of wicks of the lamps and of lamp chimneys required. Regarding the purchase of gas for lighting, it should be mentioned that gas is charged for at a unit price, which, in recent years, has been steadily decreasing, so that at the present time, for instance, consumers in New York obtain one thousand cubic feet of gas at eighty cents, whereas the market price of good lighting oils fluctuates more or less. When buying oil or candles, consumers pay in advance, as it were, whereas payment for gas is made after it has been used.* The bills for gas are made out from the records of the gas meters, which are officially tested measuring apparatus, and even the quality of gas is controlled at municipal testing stations, at least so far as the candlepower of the gas furnished to consumers is concerned. Kerosene oil may, in itself, be cheaper than gas but if we add to its cost the breakage of lamp chimneys and the cost of trim- ming the lamp wicks, and for cleaning and filling the lamps, gas becomes the cheaper illuminant of the two. One great advantage lies in the convenience of gas lighting. The gas flame is instantly lighted, available at all points where gas outlets are placed, and quickly put out. Gas burners are also cleaner than oil lamps, there is no objec- tionable smell, and less heat is created and the air is polluted by products of combustion to a lesser degree than where candles or lamps are used. Finally, gas lighting involves less danger from fire than illu- mination by oil lamps, and while the portability of lamps is claimed by some to be one of their advantages, it also renders them dangerous in use, as many lamp explosions prove. What interests the consumer more than other things is the cost of an illuminant, and, as regards economy, gas lighting, in particular when the modern incandescent gas lamp is used, is ahead of all other modes of lighting, as the following comparison shows, in which the electric-arc lamp is not included, as it is not well adapted for dwelling-house illumination. The electric energy, if taken from a central station, costs in New York at. present 10 cents per kilowatt-hour. Hence the * This statement does not apply to gas burned in the more recent prepay- ment gas meters. W. P. G. 14 Gas Piping and Gas Lighting consumer obtains, for one dollar, ten kilowatt-hours, and as the incandescent electric lamp of 16 candle power uses on an average 55 watts, he can, for the expenditure of one dollar, burn the lamp 10,000 =182 hours. 55 Illuminating gas costs at present in New York 80 cents per 1000 cubic feet, and as a good incandescent gas lamp, of 60 candle power, burns about 3.5 cubic feet of gas per hour, the consumer obtains, for the expenditure of one dollar, 1250 = 357 hours. o.5 Kerosene oil costs at present in New York about 14 cents per gallon; hence, for one dollar the consumer buys a little over 7 gallons. A good kerosene lamp giving 16 candle power uses per hour 0.025 gallons, hence the consumer can burn it for one dollar 7 - = 280 hours. 0.025 Summarizing the above, a consumer obtains for one dollar, with the incandescent lamp, 182 X 16 = 2912 candlepower-hours; with the kerosene lamp 280 X 16 = 4480 candlepower-hours; with the incandescent gas lamp 357 X 60 = 21,420 candlepower-hours. Hence, he obtains the greatest amount of illumination by using the incandescent gas lamp, and the least by using the incandes- cent electric lamp. To put the above in another form: One electric incandescent lamp costs per hour 55 X 10 1000 one incandescent gas lamp 3.5 X 80 0.55 cents; 1000 one kerosene lamp 0.025 X 14 = 0.35 cents; Advantages of Gas as an Illuminant 15 hence, the incandescent gas lamp furnishes the highest illumi- nation for the least expenditure of money. In this calculation it has been assumed that the life of the mantle, of the carbon fila- ment in the electric lamp, and of the wick in the oil lamp are about the same. In making the above computations, I have followed closely the statements made in an excellent little German pamphlet, entitled ''Xo house without gas," published and widely distributed by the German Association of Gas Engineers, but the figures and prices have been adapted to current American conditions. Another statement, somewhat similar in results, is taken from O'Connor's Gas Engineer's Pocketbook, and is as follows: The relative costs of lighting with gas flames, oil lamps, and electric lamps are as 305 for Welsbach burners, 449-589 for petroleum lamps, and 1954 for electric incandescent lamps, and according to Prof. D. E. Jones, the number of candlepower- hours which can be provided at the same cost for different illumi- nants are: for wax candles 33 hours; for stearine candles 77 hours; for electric incandescent lamp 440 hours; for coal gas burnt in flat-flame burner 625 hours; for large petroleum lamp 2250 hours; for a Welsbach incandescent burner 2300 hours; for a Welsbach incandescent burner with water gas 4350 hours. It should be mentioned that in the above comparisons no con- sideration was given to the latest development of electric lamps, like the Nernst, Osmium, Tantalum and Tungsten lamps, which, although from 8 to 10 times more expensive in first cost than ordinary carbon filament lamps, are much more economical in the use of electric power (requiring about 1.5 as against 3.5 watts per candle power), and which also prove to be more durable and lasting, some of these lamps having a life of 1000 hours and more. CHAPTER IV. ADVANTAGES OF GAS AS A SOURCE OF HEAT AND POWER. WHILE gas was at first manufactured and used for illuminating purposes only, other uses suggested themselves, as soon as the price of gas was reduced. The greatest stimulus to the use of gaseous fuel for domestic, industrial and commercial purposes was, perhaps, given by the development of the abundant, and therefore cheap, natural-gas supply. But the use of manu- factured gas for cooking, heating, and for running engines became likewise quite popular, largely because of its superior convenience. The advantages which gas offers for lighting purposes are even to a higher degree true of the use of gaseous, as compared with solid or liquid fuel. One of the greatest advantages of gaseous fuel over coal or wood lies in the fact that a fire may be started instantly without previous preparation, and that the fire almost immediately gives off a high degree of heat, while its intensity may be regulated at will and stopped entirely in a moment by the mere turning off of the stop-cock or gas valve. It is for this reason, chiefly, that we find an ever-increasing use of gas fuel in our homes, in small workshops, and in large industrial establishments. It is sometimes asserted that the advantages of gas for cooking become specially manifest where cooking is done on a large scale. This may be true; but, on the other hand, it is a fact that gas as fuel is becoming of the greatest importance in the dwellings of people of small means. A gas cooking stove or range is convenient, time- and labor- saving; it does away with the various manipulations necessary where coal, wood or peat are used as fuel; there is no periodical stirring and shaking of the grate, and no refilling of the fire pot, while less attention is required by the fire. The use of gaseous fuel means a much greater cleanliness in the kitchen, as there is no residue from the fire, no ashes, no soot, smoke or dirt, nor does the chimney flue require cleaning. Very little heat escapes into the chimney, whereas in a coal range there is not only much heat 16 Advantages of Gas for Heat and Power 17 lost which passes up the chimney, but the top plate also radiates a good deal of objectionable heat, and in this respect the use of gas cooking ranges is much appreciated in summer time, for the kitchen is thereby kept cooler. There is also no trouble such as is caused where chimneys smoke or do not draw well. Add to this the numerous other advantages, for instance, the well-observed fact that viands cooked by gas are more palatable and lose less in weight, that roasted meats retain more of the juice; also the fact that no space is required in the kitchen for the coal scuttle and the kindling wood, that coal bins are not w r anted in the cellar, that there is no purchase, transportation and storage of kitchen fuel, and finally that a gas range is ready at all times, day and night, and requires only the application of a lighted match to be put at once in full operation. In short, the use of gas for cooking purposes is becoming more popular from year to year, and rightfully so. In view of all that has been said above, it seems quite proper to ask the question: What are the disadvantages of cooking by gas? And the only possible reply which can be made is, that it must be more costly than other methods, because considering the heat units obtained from coal as compared with those from gas, gaseous fuel appears to be at a disadvantage. A ton of coal of average quality and costing $6.25 contains about 2000 X 12,000 = 24,000,000 heat units, whereas 7,800 cubic feet of gas, the equivalent in price (gas at 80 cts. per 1,000 cubic feet), yield only 7,800 X 710 = 5,538,000 heat units. Hence, heat derived from burning gaseous fuel costs at least five times as much as heat derived from burning a medium quality of coal. Nevertheless, cooking by gas is actually cheaper than with coal, always supposing there is no wasteful burning of gas, because a gas fire is extinguished quickly, giving off no further heat, whereas a coal fire must be kept burning until it goes out, even when no longer required. Much saving can also be effected by a nice regulation of the cooking burners. In general, it may be stated, that while in coal ranges only about 10 per cent of the 18 Gas Piping and Gas Lighting heat generated is utilized, the rest passing up the chimney or heating the kitchen, in gas ranges this percentage is usually 50 per cent or even more. Many experiments, conducted by gas authorities to ascertain the actual facts, show that with proper management cooking by gas is really cheaper than by coal. Statistics seem to confirm the growing popularity of gas as a kitchen fuel, for some gas works report an even larger day than night consumption, which fact cannot be explained in any other way than by the increased use of gas in cooking. It is also pleasant to record the fact that people of small means have, in the last ten years, become more and more aware of the advantages of gas, have relinquished their former prejudices that gas for cook- ing is an expensive method, and are now full of praise for the economy effected by using gas. Nothing could be more errone- ous than to suppose that cooking by gas is a luxury to be in- dulged in only by well-to-do people. There are a number of households, in which gas is used and properly managed in the kitchen twice a day, not only for cooking, but also for boiling clothes to be washed, heating the laundry irons, and making hot water for dish washing in gas water heaters, and where the average monthly gas bill does not exceed $3.00 in the summer months and $5.00 in the winter months, including the gas for lighting. Many improvements in the construction of gas cookers and gas ranges have been made in recent years; the ovens are better ventilated, and are heated more uniformly, and better non-luminous burners are used in the top plate, which can be easily cleaned, and have an adjustable air supply, thus doing away with the former tendency of burners to light back. During the summer months, gaseous fuel may be advantage- ously used for heating the water required for bathing, ablutions, and for shaving. Not more than one cent per day is required to heat enough hot water for dish-washing purposes, by a gas water-heater supplying a kitchen faucet directly, and enough hot water can be heated for a bath in about 30 minutes with a gas consumption of about 7.5 cubic feet, costing only 0.75 cent. The use of such gas water-heaters is growing in popularity every year. In order to arrive at the cost of heating water by city gas, the Ruud Manufacturing Company, of Pittsburgh, who are makers of Advantages of Gas for Heat and Power 19 several types of gas water-heaters, had a special installation made in a house. The heater used supplied three bathtubs, three laundry tubs, a kitchen sink and three lavatories. A separate gas meter was installed on the gas service supplying the gas water-heater. The gas supplied averaged about 650 B.t.u. per cubic foot, and cost $1.00 per 1000 cubic feet. The re- sult of the reading of the meter for a period covering one and one-half years showed that the average monthly cost of gas to operate the gas water-heater including the pilot light amounted to $2.73. This sum appears to be very moderate indeed, and is explained by the fact that the kitchen boiler was, during the winter months, heated by the coal range, the gas water-heater being fitted up so as to act as " supplementary " or "re-heating" system. It should be mentioned that the pilot light used in the gas water-heater, used on the average 32 cents worth of gas per month. There are, on the other hand, some so-called automatic gas water-heaters, which require the constant burning of a pilot light, which are not quite so economical, but the smaller sizes of instantaneous heaters, in which the gas flame is controlled by a thermostat and cut down automatically to the smallest possible size, as soon as the water has attained the maximum required temperature, may be safely recommended for use. In the laundries of many public institutions the heating of irons is economically effected by means of gas; the use of gas is likewise popular in tailoring and other industrial establishments. Gas is also used in households, for warming dishes in plate warmers, for the running of domestic pumping engines, and for purposes of ventilation to create a positive upward draught in exhaust flues. The majority of advantages enumerated for gas used as fuel in cooking are equally true of the heating of rooms by means of gas stoves. But in one important respect there is a difference, because heating by gas, at present rates charged for manu- factured gas, is somewhat expensive if applied to rooms or apart- ments which are constantly occupied, and which, therefore, require gas heating stoves or gas logs to be kept burning for many hours; in such cases the use of gaseous fuel costs more than warming by the use of coal or other fuel. Nevertheless, there are numerous instances where the use of gas heating stoves is both convenient and comparatively economical, 20 Gas Piping and Gas Lighting for instance in the heating of bathrooms, or of rooms not con- stantly occupied, as in hotels, where heat is only occasionally wanted. Here again, the same as in the case of cooking by gas, the chief superiority lies in the fact that no preparations for heat- ing are required, that no fuel has to be carried in or ashes taken out and removed, that the apartments can be quickly heated, because the heat from the fully turned on burners becomes at once available, and that the heat can easily be regulated and quickly turned off, when not wanted any longer. As an auxiliary heating method, heating by gas is advanta- geous, for there are days in the fall or spring of the year when one does not need to put the regular heating apparatus in operation ; gas stoves and gas fireplace heaters are also useful in supplement- ing the regular steam, hot-water or furnace heat on extremely cold days, or for very exposed rooms; and, finally, heating by gas may be of much service in an emergency, for instance, if the coal supply has become exhausted at the time of a coal miners' strike, when coal cannot possibly be obtained at any price. There are, finally, numerous uses of gaseous fuel in manu- facturing industries, to which I can refer but very briefly. Gas is utilized extensively as a source of power in the modern gas engine, and in many smaller industries and workshops this form of prime motor competes very successfully with the steam engine, principally on account of the low operating expenses and the small amount of attendance required. The smaller machines do not require the constant employment of a skilled and licensed engineer, hence are preferred for many purposes, except where the buildings must be heated by exhaust steam from steam engines. Gas engines are now made in many sizes, ranging from 0.5 horse- power to many hundred horsepower. In the last ten years great improvements have been made in the design and constructive details of gas engines, and in the simplification and increased strength of important working parts. A gas engine consumes, according to size, on an average from 20 to 30 cubic feet of gas per horsepower-hour, at an expendi- ture of from 1.6 to 2.5 cents, whereas steam engines require from 5 to 10 pounds of coal per horsepower-hour, costing, with coal at $4 per ton, from 1 to 2 cents per hour, so that the cost of fuel, per se, is nearly the same. It is stated on good authority that more than one-tenth of the entire output of gas from gas works in Germany is used at present for the production of power. Advantages of Gas for Heat and Power 21 It may be possible that in the future a still larger utilization of gaseous fuel may be brought about, if arrangements can be eco- nomically perfected for conducting cheap fuel gas from the large coal fields to the principal cities instead of adhering to the present practice of shipping the coal at expensive freight rates. CHAPTER V./V THE ARRANGEMENT OF GAS PIPES IN BUILDINGS. GAS PIPING may be defined as the art, or process, of fitting a building with pipes intended for gas supply. It designates the trade, or mechanical labor of cutting, fitting and putting together the pipes used for the conveyance of gas for lighting, for heating and cooking, or for power purposes. Gas fitters are skilled work- men who cut, fit and put up pipes, fittings and fixtures intended for gas lighting, or for the use of gaseous fuel for heat or power. In former times, the gas piping of buildings in the United States was done by a special class of craftsmen or mechanics, and the gas fitters formed a trade entirely distinct from the plumbers. Nowadays, however, nearly all the gas piping done in buildings is carried out by plumbing contractors, though the journeymen, who do the work, are generally special gas-fitters. In exceptional instances, parts of the gas piping in houses are done by mechanics employed by the gas companies. Although this is a common practice in England and in some parts of the continent of Europe, it is not usual in the United States, except possibly in cases where gas companies do odd pieces of piping, such as may be required for a gas cooking or gas heating stove, furnished and installed by them. When a building is to be piped for gas, the first thing to do is to make a correct layout of the piping on the several floors. This layout should be based upon the general plans of the architects, which should show the location of all the outlets required for gas, whether for light, heat or power. In order to determine the sizes of the gas service, of the risers, of the distributing lines, and of the branches to these outlets, it is necessary to ascertain at the begin- ning the number of gas flames required for light, and, where gas is used for fuel, to ascertain separately the number of gas stoves, gas ranges, gas logs and gas water-heaters, and to figure up their total maximum hourly gas consumption. In counting the num- ber of gas outlets, it is necessary to take into account the number of burners, which will be required at each outlet. 22 The Arrangement of Gas Pipes in Buildings 23 The term "service pipe" is usually applied to that portion of the gas-pipe system of a building, which begins at the street gas-main and ends at the consumer's gas meter. The gas service from the street main to the inside of the cellar is always put in by the gas company, and the custom of gas com- panies in American cities is not to charge the owner for the fur- nishing and laying of the service pipe. Both the gas service-pipe and the gas meter remain the property of the gas company, and the latter 's responsibility does not ex- tend beyond them; in other words, in case of any trouble or defect in the gas supply of a house, the company looks only after the gas meter and the service pipe, and keeps both in repair or attends to the cleaning out of the same in case of stoppages, while it devolves upon the house owner to have the house pipes for the distribution of gas examined and kept in proper condition. Many gas companies, however, exercise a control over the gas pipes while they are being put into a building, and in one excep- tional case, mentioned in Chapter XVI, the gas company issues and enforces rules regarding the proper manufacture of the gas fixtures. The material for the main service-pipes from the street into the house is either cast- or wrought-iron pipe. Lead pipe is scarcely ever used for this purpose in the United States. Cast-iron service pipes, with lead-caulked joints, are used only in the case of a very large building or a group of buildings, such as public institutions, which require gas pipes four inches in diameter and upward. Large service pipes, up to and including three inches in diam- eter, are as a rule put in with wrought-iron, screw-jointed pipes, while for smaller services both lead and wrought iron are em- ployed. Usually, wrought-iron, screw-jointed service pipe is preferred to lead, at least in the United States, probably because the lead pipe is liable to sag in the trench, unless well supported, and thus dips or traps are caused in the pipe, which may accumu- late water of condensation, and thereby cause the flickering of the light, or may even cause the gas to cease flowing. In the use of wrought-iron pipes, however, certain precautions should be observed for the protection of the pipe against cor- rosion. The pipes should be laid in trenches with a firm bottom, and their outside should be coated with asphalt or coal-tar pitch, particularly where they are laid in soils containing acid or alka- 24 Gas Piping and Gas Lighting line residues, or in soils mixed with ashes, cinders, furnace slag or chemical refuse, all of which have a tendency to cause a quick destruction of the pipe by corrosion. Gas service-pipes should always be laid with a good pitch, either toward the street main or toward the house, and depres- sions or low places in the pipe should be avoided, so that no con- densed tarry vapor will remain in this portion of the pipe. It is equally necessary thatvsuch pipes be protected against frost, by laying them at a proper depth in the ground. Where gas service- pipes are necessarily exposed to the outer air, as sometimes does happen in crossing basement areas, they should be thoroughly wrapped with some non-conducting material such as is applied to steam pipes to prevent loss of heat. In addition to this, it is advisable to fasten over the pipe a slanting board, to prevent snow and ice from lodging on the pipe. In laying gas service-pipes it is always advisable to place on the line a shut-off, operated by a long key from a box in the side- walk near the curb, to control the gas supply to each house from the outside. While the shut-off is not a necessity in the case of private dwelling houses, it is required by all good building laws in the case of theaters, churches and all public buildings, and to this should be added schoolhouses, colleges, hospitals and asylums of all kinds, and workshops, factories, warehouses and large manufacturing establishments, all of which require large gas service-pipes. In case of a fire in any of these buildings it is important to have means to cut off the supply of gas from the outside. It is preferable to place this valve on the sidewalk near the curb, where it remains more accessible than when located in the pavement of the roadway. All gas shut-offs on service pipes should be of the full diameter of the pipe, and of such construction that when full open they will not reduce the available inside diameter of the gas pipe; in other words, either gate valves or round-way stopcocks of steam metal should be used in preference to globe valves or to ordinary stopcocks. The size of the service pipe is governed by the number of gas outlets to be supplied, or, what is the same thing, by the estimated total maximum hourly consumption of gas. In ascertaining this, the mistake should not be made of counting the number of gas outlets in the rooms, halls and staircases, but the exact num- ber of burners to each outlet should be designated on the plans, The Arrangement of Gas Pipes in Buildings 25 and the size* of pipe should be in proportion to the number of gas burners, a suitable allowance being made in addition for fire- place gas logs, cooking gas stoves, ventilating gas jets, supply to domestic gas motors, etc. The rule should be laid down that no service pipe, even for the smallest house, should be less than one inch inside diameter, and it is, at this day, the practice of most gas companies to run noth- ing less than 1-inch gas services, and 1} inches would be even better. While these sizes are slightly larger than called for by the requirements of small dwellings, they will prove more satis- factory in the end, as larger services are not so liable to stoppages by naphthaline, while their cost is only a trifle more. It should also be borne in mind that large supply or service pipes act, to some extent, as governors in reducing the influence of a sudden closing of a number of burners. Besides, it often happens that additions are subsequently built to a house, or to a factory, and the gas service-pipes in such buildings often become insufficient and inadequate for the service which they have to perform, unless allowance has been made in the beginning for a possible increase in the number of burners. Larger buildings require service pipes from 2 to 4 inches in diameter. The sizes of gas service-pipes may be computed from formulas for the flow of gas, which will be referred to later on, or they may be readily found in the elaborate and complete tables calculated from such formulas, a number of which are given hereafter. It is well to remember that where water gas or naphtha gas is used (the latter in gasoline gas or air machines for country houses) the sizes of pipes should be increased 15 to 20 per cent over those required for coal gas. The following condensed table of sizes of service pipes answers for all practical purposes: Burmera. Size of Service Pipe. Inches. For 1 to 15 1 16 to 25 1.25 26 to 60 1.50 60 to 100 2 101 to 170 2.50 171 to 250 3 26 Gas Piping and Gas Lighting The material used almost universally for gas pipes within the building is standard welded wrought-iron gas pipe. A great deal of steel pipe is nowadays sold in the market, but this is much more brittle, and the threads do not cut so readily or so evenly on this kind of pipe. It is, therefore, always preferable to specify or to order " genuine" wrought-iron pipe. In some of the better class of work galvanized-iron pipe is used to prevent rust accu- mulations on the inside of the pipe. Lead, tin and composition pipes are used to some extent in European cities, and chiefly in England, at least for the smaller sizes. The advantages of such pipes are, that owing to their greater interior smoothness they offer less resistance to the flow of gas, .and that they do not corrode, but it is dangerous to run them in concealed places, for nails may accidentally be driven into them causing leaks. Bends in such pipes must be made with great care, otherwise the area of the pipe may be contracted. Copper pipes are not recommended for gas piping, for it is said that a chemical compound of copper and acetylene may form as an incrustation in the pipes, where the gas supplied is insuf- ficiently purified, and this compound may give rise to explosions. Iron gas pipes are first cut to measure from the layout made by the gas-fitter; the ends are then threaded by means of sharp dies with standard threads. The burr due to the cutting must be carefully removed, and the pipe ends reamed out, since it tends to reduce the area of the pipe. The precaution is particularly important for smaller sizes of pipes. The pipes are put together with screw joints and red lead. Fittings, such as sockets, elbows, bends, tees, crosses and re- ducers, are used for the running of branches, for making changes in direction, for providing the outlets for the fixtures, etc. The better and stronger fittings are malleable-iron fittings with beads or shoulders, but for sizes above two inches in diameter cast-iron fittings are used. Black fittings often have sandholes, and for this reason it is advisable to use nothing but galvanized fittings. In screwing up the pipe and the fittings, the joints should be made entirely gas-tight without using any lubricant other than oil, or possibly some red lead. Threads which permit the pipe to screw up to the shoulder of the fitting, while the joint is still loose, should be avoided. Red lead should be used sparingly so that it may not become squeezed into the inside of the pipe where it would cause an obstruction to the flow of gas, and a reduction in The Arrangement of Gas Pipes in Buildings 27 the clear bore of the pipe. Where it is used at all, it should be put on the pipe threads and not into the fittings. Before putting pipes together, they should be blown into and examined for obstructions, and it is a good practice to tap the pipe with a hammer to cause any rust flakes to fall off. The practice, which was formerly quite a common one amongst gas-fitters, of making the joints tight by using gas-fitters' cement cannot be approved, for such cement is liable to crack* and break off when cold ; it may also become softened by the action of the gas, and if in the vicinity of steam or hot-air pipes, it is liable to melt. It is a good practice to prohibit entirely the use of gas-fitters' cement. Careless or unscrupulous mechanics often apply such cement, not only to leaky joints, but also to fittings having small sandholes. Where defective fittings are encoun- tered, the only right thing to do is to reject the imperfect fit- tings and to use only those which are perfect. Equally bad is the practice of filling up the gas pipes with water, or other liquid, or with diluted muriatic acid, to induce rusting up of the joints to make the piping tight. This prac- tice, which generally leads to subsequent troubles, owing to the stopping up of the pipes with rust, should be forbidden, in view of the fact that there is always in old houses considerable accumulation of rust in pipe systems, even where the pipes have not been so treated. Where iron gas pipes are bedded in cinder floor-fillings they should be painted on the outside with some protective coating to prevent corrosion from the outside. Risers should be controlled by round-way stopcocks or soft- seat globe- valves, placed at the foot of the line, generally at the cellar ceiling. When a gas- piping system is completed, its tightness should be tested by rneans of a force pump and a mercury gauge. The use of pressure or spring gauges is to be deprecated as they are hardly reliable for such low pressures as are applied in the testing of gas-piping systems. Where good materials are used and put together by competent workmen, there is no difficulty whatever in getting the pipe system sufficiently tight to withstand a test equal to a pressure of 18 inches of mercury in the glass tube, equivalent to approxi- mately 9 pounds pressure to the square inch. Should the mer- cury in the gauge drop, it is a sure indication that there are leaks 28 Gas Piping and Gas Lighting somewhere. Such leaks are generally found by introducing some sulphuric ether into the pipes, or else by applying soapsuds with a brush to the outside of the joints and fittings, and waiting for the appearance of soap bubbles. Split pipes or defective fittings should be at once removed when discovered by the test. (See the Chapter on the Testing of Gas Pipes.) Branches to side- wall burners are generally made 0.375 inch in diameter, and branches for chandeliers 0.5 inch. In the best practice no gas pipes smaller than 0.5 inch are used, and these are reduced at the outlet for the side-wall burners to 0.375 inch; in the same way the pipes for center lamps or chandeliers with more than four burners are made 0.75 inch in diameter. In Dresden, a municipal rule prescribes that all gas pipes which are not carried exposed should be not less than 0.75 inch. The rule is a good one, and might, with advantage, be adopted in the American gas-piping practices. In laying out the system of main distributing pipes and branches to outlets, the endeavor should be to get an equal supply of gas, to arrange the distribution in a systematic man- ner and, wherever practical, to provide a circulation system, the advantages of which are particularly noticeable in larger buildings. The greater the specific gravity of the gas, and the rougher the inside of pipes, the larger should they be. Gas-fitters are gener- ally governed by some kind of table of pipe sizes, and in using these, it is well to bear in mind a possible future increase in the number of outlets. It is always advisable to be on the safe side, as a larger caliber of pipe is never an objection, but may be, at a future time, a decided benefit. In former years the gas com- panies used to give much more attention to this matter than at present, and each company had its own rules and regulations and tables of sizes, but only a few companies publish such tables at the present time. Some of these will be given in full further on. (See Chapter VII.) Table I, on page 29, is a useful one for correctly proportioning the sizes of risers, distributing lines, and branches. The Arrangement of Gas Pipes in Buildings 29 TABLE I. Diameter of Length of Pipe in Yards. Pipe in Inches. 20 30 40 50 60 70 80 90 100 0.50 7 6 5 4 4 4 3 3 3 0.75 17 14 12 10 10 9 | 8 8 7 1.00 32 26 22 20 18 17 16 15 14 1.25 52 43 37 33 30 28 26 25 23 1.50 79 64 56 50 45 42 39 37 35 2.00 150 123 106 95 87 80 75 71 67 Number of Burners It is advisable to run several vertical gas-risers, in order to shorten the horizontal gas distribution. The main gas-risers should, if practicable, be kept accessible, or even exposed, in minor closets. All gas pipes should be run with a continuous fall of at least 1 inch in 100 feet toward the gas meter, and the greatest care is necessary to insure that the entire gas-piping system is free from any low places or sags, where water or vapor of condensation may accumulate, for this interferes with the free flow of gas and causes the annoying "jumping" of the light. Branches from running lines to ceiling outlets should not be taken directly from the bottom of a running line, because any water of condensation will run into the fixture and give trouble ; it is much better practice to start these branches from the side or top of the running lines. In the same way, it is better to run bracket outlets up from below, which can be done on all floors, except the lowest floor of the building. Xo gas pipes should be run through flues, nor should they be placed under hearthstones. Where right-angled turns in horizontal piping are made, it is advisable to use plugged tees instead of elbows, as these fittings can be utilized in making changes or additions. The floor boards over such places should be fastened down with brass screws. All outlets should be well strapped and fastened; all drop fixtures as well as the nipples for side-wall fixtures should be perfectly plumb or at right angles to the surface, from which they project. The nipples should be cut off the exact length for putting on the gas fixtures. In order to measure the amount of gas consumed in buildings, gas companies furnish to their customers, and set, generally free 30 Gas Piping and Gas Lighting of charge, a gas meter or instrument measuring the consumption of gas. The general construction and accuracy of these will be referred to in a later chapter. (See Chapter XVII.) It is usual to fit up the gas meter in a cool place in the cellar. The location of the meter should be such that the index of the same can be readily read by the gas companies' inspector. Where much gas is used for fuel purposes, in cooking or heating, and also where gaseous fuel is sold at a lesser price than gas for lighting purposes, many gas companies furnish and set a second meter, which regis- ters the consumption for cooking, etc., separately from that for lighting a building. In the best practice separate gas-service lines are run to all places where gas is to be consumed for either heating or cooking, and such branches are never taken from the nearest line which supplies gas for lighting. A badly executed gas-lighting system is often one of the great- est troubles a house owner has to contend with ; it leads to con- stant annoyances, and may cause injurious leaks and sometimes dangerous gas explosions. Gas piping costs but a very small fraction of the total cost of a building, hence it is advisable to have it done only by thoroughly competent and honest con- tractors. In dwelling houses erected by speculative builders this work is usually done very badly. The lowest-priced gas-fitter is chosen ; no specification is given for the work, and the fitter seldom takes the interest in his work which the importance of the subject requires. Being chiefly concerned with completing his contract as cheaply as possible, without regard to safety and efficiency, he buys pipes and fittings of inferior quality, and of insufficient size, employs mechanics without intelligence, experience or integrity, and compels them to do their work in a hurry, to use as little material as possible, while they in turn pay no attention to the proper laying, supporting and jointing of the pipes. When the piping is completed the enterprising builder goes to the cheapest gas-fixture store, buys ill-constructed fixtures with inadequate tubing and inferior burners, and has these put up in a hurry. The buyer or occupant of the house soon encounters endless annoyances, resulting from the insufficient size of the gas pipes, from insufficient or careless support of pipes, from leaky joints, split pipes or fittings with sandholes. The gas will burn badly, the flames will jump, and there will be numerous leaks of The Arrangement of Gas Pipes in Buildings 31 gas. It is a matter of common occurrence that in such houses the piping has to be entirely reconstructed to get proper illumination, and to get rid of the gas leaks which endanger the health of the occupants and threaten gas explosions. The following editorial is taken from Building: " Installation of Gas Pipes" "If there is any one appliance more than another that is left to the discretion of the mechanic, it is the gas-fitting. Much time and care may be taken in selecting the fittings and choosing artistic brackets or chandeliers, but little thought is apt to be given to the general system of the mains, or the layout of the pipes. We have learned to study our plumbing and drainage carefully, but further than seeing that the pipes do not leak, there is little attention paid to the gas piping. " In a lengthy letter to the Boston Transcript, Mr. J. Lyman Faxon, a well-known Boston architect, calls special attention to the danger from gas fixtures. Among all the appliances that enter into the complex make-up of the modern house, there is nothing, perhaps, that invites more danger and is attended with so many fatal accidents as gas. Every paper we pick up notes some case of asphyxiation from gas, involving the lives often of several individuals in a single casualty. These fatalities, due to asphyxiation, says Mr. Faxon, 'are directly attributable to two causes: (1) improper and unscientific installation of gas-pipe systems, resulting in inequality of pressure and distribution, and (2) to the carelessness of people in turning down the gas. In my judgment, he says, comparatively few cases of fatality are due to ignorant people blowing out the gas flame.' " After explaining the nature of gas, its volatile character, he states that, ' the natural flow or direction of gas in pipes, when under pressure or free from obstructions, is upward and toward the freest combustion; it can be forced, by pressure, through down pipes, but if the pressure is unequal by reason of imperfectly disposed piping or by larger consump- tion at other points, its flow will be towards those parts of the system which are under greatest pressure or freest consumption. It is, there- fore, of greatest consequence that the pressure in any system of pipes shall be equal and constant at all points. The pressure in vertical pipes increases about ten per cent for every thirty feet of rise, and a relaxa- 32 Gas Piping and Gas Lighting tion of pressure of about five per cent for every thirty feet down, so that the difference in pressure between two burners sixty feet apart, verti- cally, will be about fifteen per cent of the initial or normal pressure, which accounts for the extinguishing of the gas flame when turned down low; indeed, I have observed flames at full cock which could hardly hold their own against the air for lack of pressure in the system.' " He condemns the present system of gas piping as being radi- cally wrong, entirely inadequate, and dangerous. As may be inferred from the above, the pressure in the upper rooms of a building is much greater than in the lower, and a burner turned down in a lower room would easily blow out, where, under the pressure of gas in the upper rooms, it would hold its light. The present system is to take the main from the meter for the whole house to some central point in the basement, thence running a central riser to the top of building and then tapping this at each floor for its supply, carrying a branch pipe ' with tap circuits or feeders to the ceiling and wall fixtures to the story below, all ending in dead ends and rarely any subdivision of the system into individual circuits, and generally the outlet taps are taken off the bottom of all horizontal lines of piping, instead of off the side or top of the pipe, thus causing all such taps and the appended fixtures to con- stitute receptacles for impure condensation instead of providing for the return of condensation to the base, and further, with no provision what- ever for equality of pressure throughout the entire system. " In illustrating the effect of this system, Mr. Faxon states the following hypothetical case, and one which is likely to occur in any building of three or more stories : ' For instance, time ten o'clock P.M., room on a lower floor. Occupant goes to bed, or ill and sleeping. Gas flame turned down to one quarter candlepower, windows and door closed, no ventilation. Twelve o'clock or later, party returns from theater with friends to room in top story, turns on all burners to full cock Presto ! Flame in lower room extin- guished by indrawing of the flame into the pipe, caused by the excessive use of gas in upper rooms. In a few moments the draught is relieved ?nd gas is ejected into the lower room through the open burner, and the occupant is asphyxiated in three or four hours, if the accident is not discovered/ "This illustration explains many fatalities that have occurred from escaping gas, and shows the need of remodeling our present The Arrangement of Gas Pipes in Buildings 33 methods of gas piping. The following is Mr. Faxon's suggestion for piping a building: 'The proper system for installing gas pipes is as follows: (1) Each and every separate story or apartment in a house, hotel, office building or other, liable at any time to contain a sleeping occupant, should have its individual circuit from the base or initial circuit. (2) Ml gas heaters and gas stoves should hkve separate circuits from the initial source. (3) All corridor, hall, and vestibule outlets should have equalizing pres- sure pipes, making complete circuits throughout individual systems from individual sources, up, around and back to initial source. I have found in practice that the sizes of such equalizing pressure pipes need to be about five-eighths the size of the main supply circuits, and that proper installation costs 20 to 25 per cent more than under the old sys- tem. (5) The individual main circuit supply pipes should be taken off a properly calculated header or drum, and each circuit cut off by a suit- able valve at the header. Thence the individual circuit should be run to a center of distribution of branch and tap circuits. All vertical pipes should be run up and not down, and all off- takes should be at the top or side of pipes, and in no case off the bottom. All piping should pitch toward the initial source for drip of condensation. The main circuit or supply pipe should be continued throughout and around the entire individual system, and returned from the farthest point to and connect with the base or initial circuit pipe. This is of the utmost importance.' "The frequent accidents from asphyxiation from gas emphasize the necessity for special attention to this matter, and for the remodeling of our laws in this respect. The necessity for equali- zation of pressure ih^ upper and lower stories is apparent, and this could, without doubt, be secured by such measures as sug- gested. With this provision no such accident as the case in- stanced by Mr. Faxon could occur. A remodeling of the laws for gas installation is evidently as much needed as are plumbing regulations. 7 ' In the Engineering Record, of September 22, 1894, appeared a lengthy editorial on this subject, and its importance must be my excuse for reprinting it here in full : " Gas Piping for Buildings." " There are few features of modern building construction which do not receive thorough treatment when the design is fortunate enough to fall into the hands of competent engineers and archi- 34 Gas Piping and Gas Lighting tects, and yet there is one very important portion of the struc- tural outfit, so to speak, of a building, which up to the present time receives no intelligent consideration whatever, except in very rare cases. We refer to the gas piping of 'buildings of all classes. The gas companies have made practically all possible advances in processes of manufacture and distribution, and while there may be unfairness in some exceptional instances, in the main the gas consumers have largely reaped the benefit of the resulting economies. "Municipal building regulations have generally prescribed fairly wise and reasonable general rules under which buildings and their various structural appointments are to be constructed, but on the question of running gas lines for proper distribution within the buildings they have been essentially silent. Architects also virtually have turned over to gas-fitters, as a general statement, the whole question of fitting the buildings which come under their design and supervision. What ought to be everybody's business seems to have been nobody's business, and consequently there probably has never been any portion of the construction and fitting of a building which has exhibited more ignorance and gross blundering than the general run of the gas-pipe plans of many structures now standing, and that is saying a great deal. As is almost or quite the invariable result in such matters the pur- chaser and the consumer are the principal sufferers. It certainly is not creditable to the architect or engineer thus to fail to properly specify, or generally to specify at all, for so important a part of his work, and no municipal regulation can be considered as complete, either in its form or operation, unless it suitably covers a class of work which so immediately affects the comfort and health of almost every human being and the welfare of every business within its corporate limits. It is the legitimate desire, of course, of the gas-fitter to reduce the total cost of his work to a minimum for his client and he gets his work as the lowest bidder; hence the result is all but a universal decrease of size of pipes in a building far below those which ought to exist for a proper supply at the points of actual consumption. Besides, a lack of proper knowledge of design causes a very general and sometimes an utterly absurd disproportion between the main and running lines and branches, which results, in connection with the fundamental difficulties of small pipes, in excessive complaints from users in many instances, and in costly and inefficient, if usually unnoticed, The Arrangement of Gas Pipes in Buildings 35 illumination or heating, and very costly alterations and additions to the piping in the modern fireproof building. "Indeed it cannot be expected that gas-fitting will be done carefully and efficiently or with materials and workmanship of excellent quality unless, like other branches of mechanical work, it is done under intelligent specifications, faithfully executed. "It is true that there have been a few very creditable efforts to remedy this state of things, but they may be said almost to be included in the excellent little work by William Paul Gerhard, 1 and perhaps the unduly short printed regulations of one or two gas companies in the country, and they have not produced any apparent improvement in the general situation. " Since the advent of high buildings with fireproof floors, and the demand for gas for cooking and heating has arisen, the embar- rassment due to the causes cited has been more pronounced. In view, therefore, of the interests involved, the Engineering Record, in pursuance of its policy to elevate and advance all branches of building construction, submits to architects and engi- neers, as well as municipal authorities, a general system of speci- fications and rules under which buildings may be fitted with gas pipes so as to produce the greatest excellence in design and the most efficient and economical use of gas. After a very thorough examination of the whole question, and after many conferences with large firms of gas-fitters, engineers of gas works, and others directly interested in the attainment of the desired end, the specifications, tables, and rules, which we print in another column, have been prepared. These regulations have been made essen- tially to agree with the few best efforts which have already been made for the same purpose; they involve no conditions incon- sistent with the best interests of gas consumers, gas producers, or gas-fitters, but they have been based upon such reasonable con- ditions as will secure in all respects the best practice to all those departments of gas interests. The tables showing the sizes required for the prescribed number of burners, logs, heaters, and ranges are based upon a very careful and thorough investigation, both analytical and experimental, in regard to the flow of gas through the pipes of the maximum lengths indicated. The resulting sizes are in some cases a little larger than hitherto pre- scribed, while in other cases they are not; but in all cases they will insure the free flow of the necessary volume of gas, and thus l " Gas Lighting and Gas Fitting." Third edition. 36 Gas Piping and Gas Lighting entirely avoid the annoyances and loss due to too small pipes. The slight increase of cost of piping from this source is too small to be appreciable in the total cost of any building whatever. "Should it be desired by architects or engineers, these general regulations can be easily supplemented by other clauses or para- graphs designed to cover special cases or details which it would not be proper or suitable to recognize in the concise regulations designed to meet the purposes of those w T hich we print. We commend these specifications to the most -careful and favorable consideration of architects, gas companies, and the building departments of cities. They have been carefully and rationally designed to fill a gap in building specifications and general regu- lations which has been the cause of most serious and widespread annoyance and loss." " Essential Requirements for the Gas Piping of Buildings." (From the Engineering Record). "As the result of a special investigation the following tables and recommendations are submitted as the basis for proper speci- fications for the gas piping of buildings to meet the demands of modern requirements for lighting, heating, cooking, and man- ufacturing : TABLE II. SIZES OF GAS PIPES, MAXIMUM LENGTHS AND MAXIMUM NUMBER OF BURNERS (AT 6 CUBIC FEET EACH). Diameter of Pipe. Maximum Length. Maximum Number of Lights. Inches. Feet. f 20 2 30 3 1 40 6 1 60 10 H 70 15 H 100 30 2 150 60 The Arrangement of Gas Pipes in Buildings 37 TABLE III. SIZES OF GAS PIPES FOR GAS LOGS AND COOKING RANGES. Diameter of Pipe. Maximum Length. Gas Required for Inches. Feet. * 100 1 cooking burner or 1 gas log. 100 2 cooking burners or 2 gas logs. 1 100 Gas cooking stove with 4 burners or 4 gas logs. H 100 Larger gas ranges or 7 gas logs. Gas logs and burners of cooking ranges are assumed to have a consump- tion not exceeding 35 cubic feet per hour. For a larger consumption increase the size of pipe supplying log or range. General Requirements. 1. All lines of piping throughout the building, except drops, must be laid with grade so as to drip or drain back into the risers, with no depressions to hold condensation. Drips with drip pipes where needed must be provided at meters and at such other points as the plan of piping may render necessary. 2. No riser must be less than three-fourths inch in diameter in any case, and all risers must be covered up on inside partitions so as to be thoroughly protected from freezing. Wherever risers or other pipes cannot be guarded in this manner, they shall be pro- tected from frost by special and effective coverings. 3. Wherever practicable all piping shall be exposed, but piping that must be concealed shall first be thoroughly inspected by the gas company, and the gas-fitter shall give due notice when the piping is ready for inspection. Unexposed piping must be so concealed as to be readily accessible in case of examination or repairs. Wherever practicable, as in floors, the * concealment shall be made by boards over the pipes, secured by brass or other non-corrosive screws. 4. In cases where extensions are made, care must be taken to extend with such sizes that the rules already prescribed shall be maintained. 5. All drop pipes must be left perfectly plumb and well secured in that position. 6. Long runs of piping must be firmly supported at frequent intervals so that no sagging nor depressions can occur in which condensation can collect. 38 Gas Piping and Gas Lighting 7. If pipes run across wooden beams or joists the requisite cutting, notching, or boring shall never be more than 2 inches in depth nor more than 3 feet from bearings, and as near the latter as possible. 8. Lines of piping shall not be placed under tiled or parquet floors, marble or other stone or metal platforms, or under hearth stones, unless the local conditions render such procedures impera- tively necessary. 9. All pipes shall be of the best quality of wrought-iron welded gas pipe, and all fittings, including couplings, elbows, bends, tees, crosses, reducers, etc., under 2 inches diameter, shall be extra heavy malleable fittings ; those of larger diameter may be of cast iron. These pipes and fittings may be plain, galvanized, or made non-corrosive by any effective method. 10. Pipes and fittings are to be put together with screw joints and red lead, or red and white lead mixed, with joints made per- fectly gas-tight. 11. All pipes shall be firmly and safely secured in position with hooks, wrought-iron straps, or hold-fasts, secured with screws at close intervals, so that continued use in proper line and grade may be effectively secured. 12. Meters shall be placed where they will be most conven- iently accessible for reading the index and for examination and repairs, and when placed on the walls the minimum height above floors shall be 2 feet for the bottom of the smallest meters, and the maximum height shall be 8 feet for the top of the largest meters. The sizes of connections shall be as follows : TABLE IV. 3-light . | inch diameter 60-light 2 inch diameter 5-light $ inch diameter 100-light 2 inch diameter. 10-light 1 inch diameter 150-light 2 inch diameter 20-light 1 inch diameter 200-light 2J inch diameter 30-light li inch diameter 250-light 3 inch diameter 45-light 1 inch diameter 300-light 4 inch diameter 13. The completed piping shall be tested by some competent authority, who shall give a written certificate of the results before any of it is covered at any point. All outlets shall be tightly capped and the whole system shall be tested preferably with a mercury gauge, or by a low-pressure spring gauge which The Arrangement of Gas Pipes in Buildings 39 has been recently and authoritatively tested by a mercury column. When air is pumped into a completed system of pipes until the pressure reaches 12 inches of mercury and stands or remains stationary for five minutes, or if the column of mercury does not fall more than 1 inch per hour, the system may be con- sidered satisfactorily tight. Otherwise leaks must be sought and stopped and the testing repeated until the preceding requirements are satisfied. While extensions to completed systems are made the same tests shall be applied to the ex- tensions before they are put in use. In the case of large build- ings the entire system may be tested in suitable sections." I will close this chapter by giving a brief summary of points which building superintendents should bear in mind when the building is being piped for gas: Summary of Chief Points to be Observed in Piping Buildings for Gas. 1. The layout of the pipe system to be arranged in ample and propor- tionate sizes according to the table of sizes of gas pipes for lamps, gas logs, gas cooking ranges, and for gas engines. 2. All gas pipes to run to fixture outlets as directly as possible. All pipes to be graded to get proper drainage back to the rising lines. No depression to exist in the running lines. All accumulation of condensa- tion to be avoided. Drip pipes or emptying siphons to be put in wherever needed. 3. Xo gas riser to be less than . 75 inch. All risers to be protected against cold and preferably to be placed on inside partitions. The use of several risers, and the shortening of horizontal distribution lines is recom- mended to avoid excessive cutting of timbers. 4. All large gas risers and distributing lines to be kept exposed wher- ever possible, or to be arranged so that they can be reached when future repairs or additions become necessary, without entailing damage to walls or floors. Smaller gas pipes, when to be concealed, to be first inspected and tested. All concealed pipes in floors to be rendered accessible by boards secured by brass screws. 5. All side outlets to be fed by risers rather than drop pipes where it is possible to do so. 6. Additions and extensions to the gas piping of a building to be governed as regards sizes and number of burners by the table. 7. All long horizontal runs of piping to be firmly supported. 8. Joists to be cut or notched not more than two inches in depth, nor more than two feet from bearing walls. 40 Gas Piping and Gas Lighting 9. No gas piping to be placed under tile or parquet floors, marble, stone or metal platforms, or hearth stones. 10. The gas pipes to be of welded wrought-iron. The fittings under two inches to be extra-heavy beaded malleable-iron fittings, to be plain, galvanized, or otherwise made non-corrosive. Fittings larger than two inches to be of cast iron. 11. The joints in the piping to be screw joints, to be made perfectly gas-tight. Red and white lead mixed to be used as a lubricant for the threads. 12. All gas pipes to be held securely in position by wrought-iron straps, hooks, hold-fasts, and screws. 13. Gas meters to be placed in accessible positions for the sake of the reading of the meter, but so as to be protected from injury. Gas meter connections to be of iron pipe ; no lead connections to be used. 14. The gas-piping system, when completed, to be tested. All outlets to be tightly capped, and the whole piping to be tested by mercury gauge and air pump, the testing pressure to be from 12 to 18 inches of mer- cury (6 to 9 pounds per square inch) ; the gauge not to fall more than . 25 inch per hour. All leaks to be sought and to be repaired and the test to be repeated. All extensions to be tested in the same way. All larger buildings to be tested in sections. CHAPTER VI. SPECIFICATION FOR GAS PIPING FOR COAL OR WATER GAS. IN piping a building for gas, it makes some difference whether the gas supplied is manufactured water or coal gas, or whether it is natural gas, machine-made air gas, or finally acetylene gas. In this chapter I give a specification prepared by me and suitable for manufactured city gas. In later chapters special specifications and rules are given governing the piping where other kinds of gas are intended to be used. GAS-PIPING SPECIFICATION. Gas Service. To be of wrought-iron pipe, of ample size; to be run into the building with pitch back to street main, where possible; or else to be provided with siphon, or drip pipe and emptying plug, where service must necessarily be graded toward the house. Gas service to be protected from frost wherever necessarily exposed. Gas Meter. To be preferably a dry gas meter; to be of ample size; all connections to be preferably of wrought-iron pipe and tube of full bore. Fittings to be beaded malleable-iron fittings. No lead meter connec- tions to be used. Meter to be set in a cool, ventilated, well-lighted place, easy of access, but protected from accidental injury. House Gas Pipes. To be of a good quality of welded wrought-iron pipe, preferably galvanized. Steel pipe, being somewhat brittle, is not so good; lead gas pipes should not be permitted. Cast-iron pipe is sometimes used for services larger than 2 . 5 or 3 inches in diameter. All pipe to be examined and blown into, before being used, to guard against obstructions. Pipe Fittings. To be of malleable iron, preferably beaded fittings; fittings to be selected and examined for sandholes ; galvanized fittings to be preferred. In making turns or bends, use fittings in preference to bending the pipe. Joints. To be screw joints. Use red and white lead mixed, or boiled linseed oil in joints. Use precaution not to get any lead on the inside of joints. 41 42 Gas Piping and Gas Lighting No gas-fitters' cement to be used on joints under any circumstances. The practice, of rusting .up the pipes by filling the gas pipes with water is bad, and should be prohibited. Unions should be avoided, particularly in concealed gas piping; if re- quired, use ground-joint union fittings. No washer joints should be permitted. All joints must be made absolutely tight. Shut-Offs. Use the best quality heavy brass work ; round-way ground-key lever cocks are preferable to valves, as they indicate at once by position of lever, whether the pipe line is open or shut. Valves, if used, should be soft-seat brass valves. Iron valves are not to be permitted, as they quickly corrode from the action of the gas. Hooks, Straps, and Clips. All pipes to be well fastened by hooks, straps, or clips of wrought iron not of cast iron. Use screws for fastening pipe hold-fasts. No bent nails or common hooks should be used to hold gas pipes in position. Cutting of Floor Joists. This should never be done by the gas-fitter. The carpenter to d^tt the cutting, and beams should not be notched, bored, or cut more tflv two inches in depth, and never farther away from wall or bearing, Hpporting the beams, than two feet. Sizes of House Pipe^ Xo pipe to be less than three-eighths inch ; it is better to make 0.5 inclPbhe minimum size. In determining sizes of pipes, follow Table II for sizes of house pipes for gas lighting (see page 36), and Table III (see page 37) for sizes of gas pipes for gas ranges and gas logs. Make all piping ample in size. Arrangement of Gas Piping. No risers to be placed in outside walls. No riser to be less than . 75 inch. A number of separate risers is desirable; these should be connected at the top, for a better circulation of the gas, and also to avoid undue varia- tion in the gas pressure. Another method of accomplishing this is to have separate risers for each floor. For gas logs in fireplaces, run entirely separate risers, one for each group of vertical fireplaces. Provide a separate riser for the gas cooking range in the kitchen. Provide a separate riser for the gas water-heater, also for the gas laundry- irons. A separate meter for gas, used in cooking or heating is desirable. Larger risers to be kept exposed in closets; smaller pipes to be tested before being covered up or plastered over. Running lines in floors to be kept accessible by floor boards, secured with brass screws instead of nails. Specifications for Gas Piping 43 Run all branches for side or wall fixtures up from below, and do not drop them from above (except in the cellar). Place no running gas lines under tiled floors or hearths. Run no gas pipes through flues. Supply drop fixtures from "branches, taken off from side or top of run- ning lines; never drop the branch from the bottom of a line. All horizontal gas pipes to be run with sufficient fall back to the riser; the horizontal run at cellar ceilings to have a fall toward the gas meter. All long horizontal runs between floor beams to be well supported to avoid sagging and traps. Avoid all condensation of gas in pockets or depressions. Keep gas pipes and risers away from pipes or flues of the heating apparatus. Gas Outlets. Place no gas outlets behind doors or too near window trims or curtains. Place outlets for side-wall fixtures at proper height, and center fixtures in the exact center of the room. At completion of gas piping, check off all outlets from plans. ^take all nipples and drops plumb, and of proper length for the fixtures. Test of Gas-Pipe System. The entire gas piping, when completed, and before plastering is begun, to be tested by a gas-fitter with an air pump and a mercury gauge (22 inches long) ; spring gauges are not reliable. Test the pipe system under a pressure equivalent to a column of mercury in gauge, 18 inches high (9 pounds pressure). The mercury in the gauge must stand one hour without indicating a greater fall than 0.25 inch per hour. All leaks and defects, which the test reveals, to be searched for with ether or by the application of soapsuds; the same to be made good by gas-fitter. Xo split pipe or broken fitting, or fitting having sandholes, to be repaired with cement or solder. In large buildings, test gas piping in sections. After the test, have a number of capped outlets opened slowly, on each of the floors, to make sure by the falling of the mercury in the gauge that the entire piping has been under the test, and that no parts are acci- dentally or intentionally disconnected. After test, leave all outlets capped tightly. When alterations in the gas are made, or additional burners are put in, test the altered work in same manner as in the first test. Before the gas fixtures are hung or put up, the gas-fitter is to repeat the test in the presence of the contractor for the gas fixtures, so as to demonstrate to him the tightness of the entire piping. This leaves the fixture man responsible for any leaks discovered when the gas is first turned on at fixtures. After fixtures are hung, the contractor for the fixtures to apply another pressure test, with three inches of mercury in the gauge. CHAPTER VII. RULES, TABLES AND REGULATIONS OF GAS COMPANIES AND OF BUILDING DEPARTMENTS. ONE of the chief faults of gas piping, as commonly done by gas-fitters, is that too much small pipe is put into the work. To determine by calculation the sizes of pipe required, at least for the main risers and distributing lines, appears to the ordinary gas-fitter to be an ultra-refinement not worthy of a serious thought; but, worse than that, even the handy tables, gotten up for the purpose of rendering tedious calculations unnecessary, are neither consulted nor followed by him. Before giving a number of rules and regulations of gas com- panies, I should, perhaps, discuss briefly the flow of gas through pipes, and the formula used to determine the theoretical dis- charge. Many of the tables, embodied in some of the rules given later on, should be used cautiously, because the sizes and gas discharges therein given apply to large and smooth pipes. For this reason the advice will be found in some of the tables to increase the sizes, in case rough or old iron pipes are used. The English tables generally are based upon the assumption that the gas pipes are of smooth lead, a material which is not used in the American practice of gas-fitting. But even some of the American tables recently published (for instance those of the United Gas Improvement Co., of Philadel- phia) have increased the required pipe sizes materially to make proper allowance for partial stoppages, due to gradual accumu- lations of rust and condensed naphthaline in the pipes. The formula almost universally used for the flow of gas through pipes is that by Dr. William Pole, and reads as follows: Q = 1350OOCOCO> T-iiao} GO-^T-IOCOCOC^IOIOOOSCOCOOOIOCO OOr- IIO COiOC-*< ' oioeoco i 300 1253 3 450 1977 4 600 4059 Use the next size larger when the length in the table for a given capacity must be exceeded. Never run a fuel line smaller than 0.75 inch. Never run a supply pipe to a gas engine less than 1 inch. Always make a run of pipe for a hot plate of 0.75-inch pipe, unless you are sure the hot plate will never be replaced by a gas stove. Always, in determining the size of pipe to be run, follow the table for 78 Gas Piping and Gas Lighting gas consumption of various apparatus, given under " Instructions for setting meters." Ask for special instructions when you are running piping for special fuel apparatus. BRITISH REGULATIONS AS TO INTERNAL GAS FITTINGS.* 1. The company will in all cases lay on the service pipe, conveying the same through the outer wall of the premises to be supplied with gas. 2. The main cock must be attached to the end of the service pipe within the building, and close to the outer wall. 3. The gas meter must be placed perfectly level, either on the floor, or on a substantial support, and within 2 feet 6 inches of the main cock. 4. The piping attached to the meter, whether inlet or outlet, must not be smaller in internal diameter than that of the meter unions. 5. The following are the sizes of the meters, and their measuring capacity, from which the number of lights which they supply can be readily calculated : Size of Meters. Size of Inlet and Outlets in Inches. Measuring Capacity per Revolution in Cubic Feet. Measuring Capacity per Hour in Cubic Feet. 2-light . . . ] ! A 12 3-light . . . : i 18 5-light . . . 1 ! 1 30 10-light . . . 1 * 60 1 5-light . . . 1 I 90 20-light . . . 1 J i 120 30-light . . . 1 H 180 50-light . . . 1 2* 300 60-light . . . 1 3 360 80-light . . . 1 4 480 100-light . . . 2 5 600 150-light . . . 3 7| 900 200-light . . . 3 10 1200 250-light . . . 4 12| 1500 300-light . . . 4 15 1800 400-light . . . 4 20 2400 500-light . . . 5 25 3000 600-light . . . 5 30 3600 To ascertain the number of burners which any size of meter will supply, divide the measuring capacity per hour by the quantity of gas per hour which each jet is estimated to consume. Example: What number of burners consuming 4 cubic feet of gas per hour will a 20-light meter supply? Then 120/4 30 burners. * From Thomas Newbigging's "Handbook for Gas Engineers." Rules, Tables and Regulations of Gas Companies 79 6. The following are the sizes and lengths of iron, lead, or composition tubes to be used according to the number of ordinary burners. (The table is omitted as it is substantially the same as the one adopted by the Consolidated Gas Co. of N.Y.) 7. The tubes or pipes must be laid with proper fall, and in such a manner that they are easily accessible, and protected from liability to damage. Attention is to be given to leaving a space round them at such places as wall crossings, etc., where fracture or crushing of the pipes might be caused by the subsidence of the building. The joinings of the tubes and pipes are to be made in the most solid and substantial manner; and carefully rounded bends (not elbows) are to be used wherever the direction of the pipe is changed. 8. Floor boards covering pipes must be secured with screws, so that they may be easily removed to afford access to the pipes, especially at the points of connection. 9. On the completion of the work of fitting, and before the piping is covered up, notice thereof must be given in writing to the gas manager, who will cause an inspection to be made of the work, and if found in accordance with the regulations herein contained, it will be passed by the company, and the gas turned on. 10. If the regulations are not conformed to in every respect, the com- pany reserve the right to refuse a supply of gas until the necessary alterations are made. 11. Gas-fitters complying with these regulations have their names registered on the company's list of approved gas-fitters, and they are at liberty to designate themselves " authorized gas-fitters." Repeated negligence will cause the license to be withdrawn. The Table of Pipe Sizes of the Committee of North British Gas Association is substantially the same as the one adopted by the N. Y. Consolidated Gas Co. This table is the standard of the principal English gas works. Services should never be undersize, as the difference in cost is not proportionate to the advantage. For gas stoves the following provisions must be complied with: Average Inside Size of Oven. Distance of Stove from the Meter. 11 in. X 11 X 14 in (If {'If under under 30 60 ft., ft., i-in. Hn. pipe pipe required required 14 in. X 14 X 24 in (If ilf under under 30 60 ft., ft., l-in. *-in. pipe pipe required required 15* in. X 15* X 24 in. ... (If Uf under under 30 60 ft., ft., l-in. l-in. pipe pipe required required 19 in. X 18 X 24 in (If ilf under under 30 60 ft., ft., l-in. H-in. pipe pipe required required 80 Gas Piping and Gas Lighting TABLE TAKEN FROM THE MUNICH GAS REGULATIONS OF 1890, Length of Size of Pipes. Pipe in Meters. fin. iln. fin. fin. 1 In. l In. l In. 2 In. 2 3 10 18 30 60 120 180 400 4 3 8 16 25 50 100 150 320 6 2 6 13 20 40 80 120 260 8 2 5 10 15 32 64 100 220 10 1 4 8 13 25 50 80 180 15 1 3 5 9 20 40 60 155 20 2 5 8 17 35 55 132 25 1 4 7 15 30 50 120 30 1 4 6 12 25 45 112 35 3 5 11 22 40 103 40 2 4 10 20 35 96 45 2 4 9 19 30 88 50 1 3 8 17 28 80 60 1 3 7 16 26 70 70 2 6 15 24 65 80 . 2 5 14 22 60 90 . . . 1 4 13 20 55 100 . . 1 3 12 18 50 150 2 9 15 43 200 1 8 13 36 250 7 12 30 300 ... 6 11 25 No pipe to be less than f inch. The table gives the number of burners, each at 5 cubic feet (142 liters). TABLE OF SIZES OF SERVICE PIPES, BY D. MONNIER, FORMERLY ENGI- NEER-IN-CHIEF OF THE MARSEILLES (FRANCE) GAS WORKS. Number of Burners. Size of Service Size of Service in Millimeters. 1 to 5 f inch 20mm. 6 to 10 1 inch 25 mm. 11 to 20 li inch 30mm. 21 to 30 1 inch 35 mm. 31 to 40 If inch 40 mm. 41 to 60 If inch 45 mm. 61 to 80 2 inch 50 mm. 81 to 100 2J inch 55 mm. 101 to 150 2\ inch 60 mm. 151 to 200 3 inch 70 mm. CHAPTER VIII. PIPING FOR NATURAL GAS. IN certain districts of the United States, extensive use has been, and is still being, made of natural gas, and as it is in many respects different from manufactured or city gas, it seems desirable to devote a short chapter to it, and to refer to some special rules and regulations necessary for its proper and safe use. Before giving these rules, it may be of interest to give a brief review regarding the history, production, composition, trans- mission and utilization of natural gas. Natural gas is an inflammable gas, generated in large quanti- ties by the decomposition of vegetable matter in the deeper strata of the earth; the gas is found in porous rock, chiefly in the vicinity of the coal fields and in the oil regions. Many of the rocky strata, which carry oil in their deeper parts, yield gas in their higher layers. Natural gas has been known since ancient times of history. It occurs in the petroleum oil regions of the Caucasus, in Italy, in Alsace, Persia, China, Northern India, and in many localities of the United States. Near the oil wells at Baku, on the western shore of the Caspian Sea, on the southern coast of the peninsula Apsheron, numerous gas wells exist, chiefly at a place called Surachanah, and these gas springs are known as the " eternal burning fires." Probably the largest supply of natural gas occurs in the United States, where it was first discovered about the year 1821 at Fredonia, N. Y., Many gas wells have been bored in the oil regions of Western Pennsylvania, also in West Virginia, in Ohio, Indiana, Illinois, and in smaller quantities in some other states. Since about 1840, natural gas has been used quite extensively as fuel. It has been transmitted in pipe lines for very long distances to the great cities, like Buffalo, Pitts- burg, Detroit and Chicago, and many villages and towns in the gas-well regions are lighted at night with the gas. 81 82 Gas Piping and Gas Lighting According to chemical analysis, natural gas is a mixture of marsh gas with other hydrocarbons, and with some hydrogen, carbonic acid, and nitrogen. Marsh gas is its principal constit- uent, the amount being in some cases as high as 75 per cent. The illuminating power of natural gas is far below that of coal gas, but it can be improved by carburetting, or else by burning it in Welsbach incandescent mantle burners ; on the other hand, it has one-third more heating value than coal gas, hence it is largely used as fuel, not only in industrial establishments, but also in dwelling houses in cities supplied with natural gas. This gas is obtained from the earth by drilling or boring wells, much in the same manner as is done for oil or water. Iron-pipe casings, from 8 to 12 inches in diameter are used, with a steel shoe at the bottom of the pipe. A gas well is any well from which natural gas issues in more or less large volume. Some gas wells are driven or bored to very great depths. The locating of a gas well is about as uncertain as the locating of a well for water, except in those districts where gas has been found before. When gas is struck in such a well, the gas some- times rushes to the surface under a very heavy pressure. In some cases, water is yielded with the gas and should be inter- cepted to prevent its getting into the distributing conduits. The gas pressure generally becomes less after a number of gas wells, located not far apart, have been drilled. Owing to this high pressure of natural gas, the danger from leaky pipes, in buildings where natural gas is used, is much greater than with ordinary gas, and likewise the risk of explo- sions. Natural gas explodes violently when mixed with ten times its volume of air and then lit, hence the greatest care is required from the gas-fitters, and pressure -reducing valves are always inserted on the gas services. Much use has been made of this kind of gas for heating pur- poses, not only in open grates, but also in steam boilers, hot-air furnaces and other heaters, and for many manufacturing indus- tries, such as puddling furnaces, foundries, enameling works, potteries, etc., it has been of inestimable value. For many years its use reduced the smoke nuisance in Pitts- burg and other cities, which formerly used bituminous or soft coal, for natural gas became the general domestic fuel for cook- ing ranges, for baking, etc. It is a clean and easily handled fuel, which when properly burned creates no smoke. Like all Piping for Natural Gas 83 gaseous fuel, it offers the advantage of leaving no ashes, cinders, or clinkers like coal. For illuminating purposes, the natural gas is not so well adapted, as the flame is neither bright nor steady. Unfortunately, the supply has in some regions of Ohio and Pennsylvania become greatly reduced, the annual output of gas is growing less every year, and some wells have ceased to flow gas altogether, particularly in the gas-bearing lime-stone regions. In Indiana, too, the natural gas supply is becoming exhausted and many wells have given out. The following statistics of the natural gas production in the United States in the year 1906, prepared by B. Hill, of the United States Geological Survey, and taken from "Mineral Resources of the United States, 1906," are of interest. In 1906 the production of natural gas amounted to 388,- 842,562,000 cubic feet, and the value of the gas product was $46,873,932. The average price of natural gas was $5.00 per short ton, whereas the corresponding price for bituminous coal in 1906 was only $1.11. "The difference in price," says the report, "is fully made up by the superior fuel efficiency of natural gas, and by the great economy of labor in its use, and the saving of cost in the removal of ashes." In 1906 there were 1871 natural gas companies in the United States. For years Pennsylvania, West Virginia, Ohio, and more recently Kansas, Oklahoma, and Indian Territory produced more gas than they consumed. In 1906 Pennsylvania reversed the conditions and borrowed from West Virginia to make up the deficiency. The transportation of the gas, in pipe lines and by pumping, is so much cheaper than that of coal that natural gas competes with coal at comparatively great distances. In the following I give the rules which the fire marshal of Pittsburg, at the instance of the Board of Fire Underwriters, issued regarding piping for natural gas. All pipes must be tested by the company's inspectors with mercury column to ten pounds pressure, from end of line, where connection is made, to end of pipes under grates, stoves, etc. The fitter should have his pump on and see that the pipes are perfectly tight before sending for the inspector. The ends of pipes under grates, stoves, etc., should first be capped, so 84 Gas Piping and Gas Lighting as to allow the stopcocks to be tested; then remove the caps and see if the cocks allow the gas to escape. In case the mercury drops, a test for leak, by putting ether in the pump, or with soap water, will be made. In no case shall a fire test be used in dwellings, offices, stores, etc. No cement of any kind shall be used for repairing faulty fittings or work; nor is the use of blind gaskets permissible. When an attempt to hide leaks is made, the name of the fitter will be kept on record in this office, and future work done by him will not be approved without a rigid examination. In running pipes in buildings no set rules can be given, except that pipes must, in all cases, when possible, be so placed that they can be easily inspected, and that in case of accident any leaking gas may escape easily. Cement wall carefully where the service pipe enters the building, and use a large pipe for the main that runs through the cellar. Provide valves to shut off gas from all risers. In running pipes through flues great care is necessary, and lead pipe for the bends should not be used. Do not run between floors or walls when any other method can be employed. Do not place cocks between floors or ceilings. Do not use any valves which require packing at the stem in places where leaking gas may be dangerous. If pipes run outside of walls, provide a drip. Allow plenty of air under the grates, so that the hearthstone may not get too hot. Set the back tile in the grate so that the unburned gas may be directed up the chimney, and not allowed to enter the room. Admitting more air under the grate, so that it will percolate through or between! the hot bars in grate, results in a cheerful bright fire from bottom of grate to the top of the fittings, and also in front. In fitting up a building all gas-fitters will be required to furnish the gas company, which is to supply the fuel, with a statement giving the number of fireplaces fitted up, and also any additional fireplaces that may be connected afterwards in the same building, so that a complete record may be had at this office. Blank forms for this purpose will be furnished by the different companies supplying the natural gas. It should be borne in mind that a leak of natural gas is not so per- ceptible as that of artificial gas, on account of the very slight odor arising from it ; and consequently more care should be taken in piping a building for its use. Fitters should also remember that accidents and explosions are likely to occur through defects in fittings and pipes; and as the introduction of natural gas is a benefit to the fitters, to the community at large, and to the insurance companies, the fitters should do all in their power to make the use of natural gas as safe as possible; and they can materially aid in this by endeavoring to put in pipes and fittings in a perfect manner. Piping for Natural Gas 85 The underwriters have issued the following rules regarding piping for natural gas. MEMORANDUM OF CONDITIONS FOR THE INTRODUCTION AND USE OF NATURAL GAS AT PITTSBURG, BY THE PITTSBURG BOARD OF UNDERWRITERS. (a) In Manufacturing Establishments. 1. When gas is to be introduced into any premises, a regulator shall be placed as remote as possible from building, by which the pressure shall be reduced to not exceeding two pounds. 2. A safety valve shall be placed between the governor or regulator and buildings, which will blow off when the pressure exceeds two pounds. 3. A mercury gauge must be placed inside of buildings which will indicate the exact pressure in the pipes. 4. All pipes leading from the regulator, and into the mills, shall be of as large diameter as possible ; on entering building it shall be elevated and carried overhead, and above all furnaces and boilers. 5. Pipes, valves, and fittings shall be carefully inspected, when the work is completed, by the Secretary of this Board, before the privilege is given to use natural gas. (6) In Dwellings. Natural gas for fuel may be used under the following conditions : All pipes and fittings must be tested to a pressure of 10 pounds to the square inch, and a certificate of such test furnished to the customer. A pressure regulator must be .placed on service pipe, and so set that the pressure at which the gas is used shall not exceed four ounces to the square inch. Gas should not be burned at night, unless the fires are all turned down low. (c) In Mercantile Buildings. Pipes and fittings to be tested same as in dwellings, and provided with regulator, pressure not to exceed four ounces. All fires must be turned off at night, unless a competent man is left in charge. Note. As nearly as can be ascertained the danger of natural gas is caused by a lack of proper control of the pressure, and it is very dangerous when the pipes are connected directly with the wells. Underwriters have concluded that a 10-ounce pressure may be considered safe, but they prefer a lower pressure. Experts on natural gas claim that the best results, as to combustion and safety, are obtained with 4 ounces of pressure. 86 Gas Piping and Gas Lighting RULES OF PEOPLE'S GAS-LIGHT AND COKE COMPANY, OF CHICAGO, FOR SIZE OF PIPE FOR NATURAL GAS FOR FUEL. Classification of Appliances. Small, portable, gas cooking stove 20 Small, portable, gas heating stove % 20 Kitchen boiler heater, when separated from range . J 20 Miscellaneous appliances consuming less than 15 cubic feet per hour each \ 20 Gas cooking ranges 30 Ordinary coal ranges, equipped for the use of gas . 30 Large heating stoves f 30 Gas logs or other grate fires f 30 Miscellaneous appliances consuming 40 to 75 cubic feet of gas per hour 1 60 Hot-air furnaces for heating 10-room buildings or less \\ 70 Hot-air furnaces for heating 10 to 15-room buildings \\ 100 Low-pressure steam or circulating water boiler for heating 10 rooms or less \\ 100 Low-pressure steam or circulating water boiler for heating 10 to 15-room house 2 140 Low-pressure steam or circulating water boiler for heating 16 to 26-room houses 2 200 Low-pressure steam or circulating water boiler for heating 27 to 50 rooms . . . ^ 3 300 Low-pressure steam or circulating water boiler for heating 50 to 80 rooms 4 400 Size of Openings in Inches. Greatest Length Allowed in Feet. CHAPTER IX. PIPING FOR AIR GAS OR GASOLINE MACHINE GAS. AIR GAS, as was stated in Chapter I, is a gas obtained by saturating common atmospheric air with the vapors from liquid hydrocarbons, like benzine or gasoline. Tit is, therefore, a - mechanical mixture, and the gas obtained is used in special burners for lighting, cooking, heating, and for power purposes., - The apparatus used for the purpose will be described in the chapter on "The Lighting of Country Houses." It should, as far as possible, be automatic, require simple manipulations, but no tedious hand -regulation. If the gas obtained is too rich, it is apt to smoke, and special ah* mixers are used with the best apparatus to avoid this fault. For lighting, it is found best to burn the gas in incandescent mantle burners. The ^precautions to be taken where gasoline gas machines are installed are discussed in Chapter XIX, and it will suffice to point out that owing to the dangerous character of gasoline and its vapors, it is necessary to have all pipes absolutely tight f] Hence the specifications for piping should be very strict. In the following I give a complete specification for gasoline gas lighting, which was published by the Progressive Age and copied by them from Domestic Engineering: SPECIFICATIONS FOR GASOLINE GAS LIGHTING. General Conditions. The owner and the architect wish the contractor to bear these points in mind throughout the installation of this work, viz : First. That although many other ways are " just as good " as the specific directions here given, it is what is called for here that the con- tractor agreed to do, and which it is intended he shall have furnished before the work is completed, unless privilege is given to deviate from that for which contract was made. Second. That not only the letter, but also the spirit, of these speci- fications are to be lived up to ; that is, in all cases wherein the good judg- 87 88 Gas Piping and Gas Lighting ment and honesty of the contractor is relied upon he shall endeavor to embody the true intentions of the designer in his work. To aid the contractor in doing this, the details of certain connections, usually left entirely to the will of the workman, are given, and which the contractor will make the disposition and the workmanship of other parts in keeping with. Third. Award of the contract is made with the understanding that the contractor will not scrimp or slight the work in any sense at any point, even though there is opportunity to do so, and take refuge behind some technicality in the wording of the specifications. In short, any- thing that is obviously needed or necessary to make a complete, durable, and satisfactory job for this particular house, with the fixtures specified, is be to furnished and put in place as a part of the work in this contract. The contractor will furnish, transport at his own cost, and put under such cover as the premises afford, at his own cost, all the material to be used on the work. He will also pay all railroad fare to and from the premises, occasioned by himself and workmen, and pay living expenses of workmen for whatever time they board in the vicinity, while the work is being put in. The contractor shall progress with this work so as not to cause unneces- sary expense or delay to other contractors. Their contracts bind them to reciprocal treatment. Setting the Apparatus. Furnish, transport to premises, and set one carburettor and air pump complete and ready for good service, of sufficient size to supply fifty (50) 5-cubic-feet-per-hour burners at the same time and capable of utilizing 86-degree gasoline with the least heavy residual product. The manufacturer's instructions for setting the carburettor and pump will be carried out to the letter, and if the maker of the machine does not so specify, the following, in addition to the maker's requirements, will be embodied in the work of setting the machine without extra cost to the owner. A union will be placed in each line connecting to the carburettor, near the carburettor. Both the air supply and the carburetted-air pipe will incline down to the carburettor from the pump and house riser, respectively. A union will be placed in the air pipe, and one in the run to the riser, within the cellar. The " runs " to the carburettor shall be below frost line of zero weather, at all points, and firmly supported by the trench bottom, direct or otherwise, in such a manner as to insure no traps resulting from settling of the dirt over the pipes. The carburettor will be set at the rear of the house not less than thirty (30), nor more than fifty (50) feet from center of rear line of house. It Piping for Air Gas or Gasoline Machine Gas 89 may be assumed that the carburet cor will be placed just outside of a line drawn thirty feet from and parallel to the rear line of the house. If more than fifty feet of pipe are required for the air-pipe " run " from foundation wall to carburettor, the owner will pay extra for it. The pump will be placed in the cellar near a wall, at a point requiring the shortest " run " to the carburettor .j Where air and gas pipes pass through the wall to the carburettor, tees will be placed with opening full size of the line, in line with the runs and openings plugged. An opening for three-eighth-inch pipe will be placed in gas pipe near pump and plugged. The gas pipe will be required to connect with house main at point marked (X) on plans which may be inferred near enough for estimating purposes by referring to specifications governing distributing pipes. *~The pump and carburettor pipes and connections shall be the full size of openings in pump and carburettor. r ~Both the air and the carburetted-air pipe will have a stopcock in cellar near exit points. In this job the owner will excavate pit and trench for carburettor and pipes and fill same when the contractor is ready. If the machine used requires a vault walled up with manhole cover and ring, the owner will provide same at his own cost. The owner will also furnish and deliver on premises, at his own cost, the gasoline with which to give the machine an actual test. The first gasoline will be put in and machine started by contractor as part of his contract. The contractor will make his bid in a way to show how much he will allow or deduct in case the owner decides to omit the carburettor and pump and their connections as hereinbefore described. House Piping. The house-service main will begin at a point convenient to reach the cellar light nearest to the rear wall, and will be one and one-half (1.5) inches in diameter to within three feet of the rising mains, which will be three in number and 1.25 inches in diameter eachu Previous to dividing the main for the three risers, a tee with a one-inch opening, plugged and turned to the side, will be put in the line. The branches for the rising mains will be provided with stopcocks, properly labeled, placed near the division of the main. The distributing pipes will be so disposed that one of the rising mains will supply all the center fixtures on the first floor, and all the bracket fixtures for the second floor. If the owner wishes two veranda fixtures, their supplies will be run from a first-floor center or a second-floor bracket fixture supply. The second rising main will supply all second-floor center fixtures, and third or attic-floor bracket fixtures. 90 Gas Piping and Gas Lighting The third riser will supply third-story center fixtures and lanterns on deck of roof, and also fixtures in pipe-way passage to storage tank. The rising mains will be full size to first, second, and third-floor ceiling joists, respectively. All other branch pipes and mains will be made one size larger than is required for same number of burners and distance on coal-gas work. Main risers will be of galvanized pipe. No pipe used for gas in this work will be less than 0.375-inch inside diameter. All first-floor bracket fixtures will be supplied from the branch which supplies the cellar fixtures. The branch for the first-floor and cellar bracket fixtures will be 0.75-inch and will be furnished with a stopcock and label in keeping with the cocks on rising mains. This arrangement of the distributing pipes provides for supplying all first-floor and cellar bracket fixtures by a branch from house main, con- trolled by a stopcock; all first-floor center fixtures, veranda fixtures, and second-floor bracket fixtures from a separate riser controlled by a stop- cock; all fixtures above level of second-floor bracket fixtures, except third-story center, deck lanterns, from a separate main also controlled by a stopcock. The pipe used inside of the house on this gas work, except rising mains, will be plain wrought iron, all new and perfect, and of the same quality as would be used for water work. The fittings will be malleable iron, galvanized throughout. The cocks will be heavy lever-handle, round- way, of brass a with hexagon ends. The thread joints will be made with asphalt varnish, except where ceiling drops screw in and where nipples are used to extend through plaster for bracket lights; these will be screwed up hot in gas-fitters' cement.* Ceiling drops will extend four inches below plaster, and must be securely fastened so they cannot be pushed in any direction at the upper end nor at a point just above the laths. Bracket openings will be set so as to protrude uniformly about one inch through the plaster. Caps on bracket outlets and drops will be screwed up only moderately tight, in gas-fitters' cement.* The fittings into which drops and bracket nipples are fitted must be fastened in place so securely that any drop or nipple for bracket may be removed and put in place again easily without cutting floor or wall. Bracket toilet light openings will be 4 feet 10 inches from top of floor; * The author does not approve of the use of gas-fitters' cement as specified. W. P. G. Piping for Air Gas or Gasoline Machine Gas 91 hall, kitchen, pantry, and bathroom bracket lights will be 6 feet from top of floor boards. Every inch of gas pipe supplying burners must have a distinct " fall," so that it will drain, either toward the carburettor or toward a fixture or bracket, preferably to the carburettor. Previous to putting in place, every fitting and pipe will be tested by exhausting the air with the lungs, and the pipe will be blown through to insure it being clear. All pipe will be well fastened in place, and so " routed " as to run between joists, if possible ; if pipe crosses joists, it must be near supports. A 0.75-inch plugged branch will be placed in main in cellar for supply to gas range, and a 0.5-inch capped opening will be placed in bathroom for heating purposes; location of opening optional with owner. If owner desires, 0.5-inch drops will be placed in parlor and library and extend 1 foot through plastering; otherwise all drops will be 0.375-inch pipe. For estimating purposes, bidders will assume that the number of openings for brackets and gasoliers, all told, will not exceed forty. If more are wanted, the owner will pay extra. The owner, or his wife, or both, will go over the plans or visit the build- ing, in company with the contractor or his workmen, for the purpose of locating the openings for fixtures, etc., before the work is commenced. In locating fixtures, due attention will be paid to probable drafts, height of ceilings, width of dressing cases to be used, and common centers of spaces to be lighted, etc. Test of Piping. When the gas pipe in the house is installed, the contractor will, at his own expense, test the entire system under air pressure sufficient to sup- port a column of mercury 10 inches high, using a mercury gauge for the purpose. If the pipe is not tight, he will stop the leaks in a permanent manner. I also quote in full a very compact and practical specification issued some years ago by the Springfield Gas Machine Co. : SPECIFICATIONS OF THE SPRINGFIELD GAS MACHINE CO., FOR PLACING GAS PIPES IN POSITION. Kind of Pipe. 1. Ordinary wrought-iron pipe, such as is used for steam or water, is suitable and proper for all kinds of gas. Kind of Fittings. 2. Galvanized malleable-iron fittings, in distinction from plain iron are very superior. The coating of zinc inside and out effectually and 92 Gas Piping and Gas Lighting permanently covers all blow-holes, makes the work solid and durable, and avoids the use of perishable cement. Precautions about Obstructions. 3. Before the pipe is placed in position it should be looked and blown through. It is not infrequent that it is obstructed, and this precaution will save much damage and annoyance. Avoid the Use of Cement. 4. What is known as gas-fitters' cement should never be used. It cracks oft 7 easily; in warm places it will melt, and it can be dissolved by several different kinds of gas. Nothing but solid metals are admissible for confining gas of any kind. Cutting Floor Timbers. 5. When pipes under floors run across floor timbers, the latter should be cut into near their ends, or where supported on partitions, in distinction from being cut in or near the centers of rooms. It is evident that a ten-inch timber, notched two inches in its middle is no stronger than an eight-inch. Side Outlets. 6. All branch outlet pipes should be taken from the sides or tops of running lines. Taking Drops from Running Lines. 7. Never drop a center pipe from the bottom of a running line. Always take such outlet from the side of the pipe. Bracket Pipes. 8. Bracket pipes should be run up from below, in distinction from dropping from overhead. The Drip of Pipes. 9. The whole system of piping must be free from low places or traps, and decline toward the main rising pipe, which should run up in a parti- tion as near the center of the building as is practical. It is obvious that where gas is distributed from the center of a building, smaller running lines of pipe will be needed than when the main pipe runs up on one end. Hence, timbers will not require as deep cutting, and the flow of gas will be more regular and even. For the same reason, in large buildings, more than one riser may be advisable. Drip Pipes. 10. When a building has different heights of post, it is always better to have an independent rising pipe for each height of post, in distinction from dropping a system of piping from a higher to a lower post, and grad- Piping for Air Gas or Gasoline Machine Gas 93 ing to a low point and establishing drip pipes. Drip pipes in a building should always be avoided. The whole system of piping should be so arranged that any condensed gas will flow back through the system, and into the service pipe in the ground. Fastening Outlet Pipes, 11. All outlet pipes should be so securely and rigidly fastened in position that there will be no possibility of their moving when the gas fixtures are attached. Center pipes should rest on a solid support, fas- tened to the floor timbers near their tops. The pipe should be securely fastened to the support to prevent lateral movement. The drop pipes must be perfectly plumb, and pass through a guide fastened near the bottom of the timbers, which will keep them in position despite the assaults of lathers, masons, and others. Height of Bracket Pipes and Length of Nipples. 12. In the absence of express directions to the contrary, outlets for brackets should generally be four feet and six inches high from the floor, except that it is usual to put them six feet in halls, and five feet in bath- rooms. The upright pipes should be plumb, so that the nipples, that project through the walls, will be level. The nipples should project not more than three-quarters of an inch from the face of the plastering. Laths and plaster together are usually three-quarters of an inch thick; hence, the nipples should project one and one-half inches from the face of the studding. Length of Drop Pipes. 13. Drop center pipes should project one and one-half inches below the furring, or timbers if there be no furring, where it is known that there will be no stucco or centerpieces used. Where centerpieces are to be used, or where there is a doubt whether there will be some or not, then the drop pipes should be left about a foot below the furring. All pipes being properly fastened, the drop pipe can be safely taken out and cut to the right length, when gas fixtures are put on. Location of Pipes. 14. Gas pipes should never be placed on the bottoms of floor timbers that are to be lathed and plastered, because they are inaccessible in the contingency of leakage, or when alterations are desired, and gas fixtures are insecure. Proving Pipes. 15. The whole system of piping should be proven to be air- and gas- tight under a pressure of air that will raise a column of mercury six inches high in a glass tube. The pipes are either tight or they leak. There is no middle ground. If they are tight, the mercury will not fall a particle. 94 Gas Piping and Gas Lighting A piece of paper should be pasted on the glass tube, even with the mer- cury, to mark its height while the pressure is on. The system of piping should remain under test for at least a half-hour. Inspection. 16. It should be the duty of the person in charge of the construction of the building to thoroughly inspect the system of gas-fitting, surely as much so as to inspect any other part of the building. He should know from personal observation that these specifications are complied with. After being satisfied that the mercury does not fall, he should cause caps on the outlets to be loosened in different parts of the building, first loosening one to let some air escape, at the same time observing if the mercury falls, then tighten it, and repeat the operation at other points. This plan will prove whether the pipes are free from obstruction or not. When he is satisfied that the whole work is properly and perfectly executed, he should give the workmen a certificate to that effect, and no job of gas-fitting should be considered complete until such certificate is issued. Sizes of Pipes. 17. The following scale of sizes of pipes and number of burners to be supplied therefrom is found by experience to be best adapted for securing a good flow of common city gas, and it is very important that it be rigidly observed, when machine or air gas is to be used. Do not confound fixture outlets with burners. In establishing the sizes of pipe in a build- ing, count the number of burners that there will be on each outlet, and have the pipes of a size to correspond therewith. Greatest Number of Feet to be Run. Size of Pipe. Greatest Number of Burn- ners to be Supplied. 20 feet | inch 2 30 feet inch 4 50 feet | inch 15 70 feet 1 inch 25 100 feet H inch 40 150 feet 1| inch 70 200 feet 2 inch 140 300 feet 2 inch 225 400 feet 3 inch 300 500 feet 4 inch 500 Finally, I reprint in full the rules for the guidance of gas- fitters, issued by the Detroit Heating and Lighting Company. These, as well as the other rules quoted, are fully applicable to modern gas piping. Piping for Air Gas or Gasoline Machine Gas 95 RULES OF THE DETROIT HEATING AND LIGHTING COMPANY To be observed by gas-fitters for properly laying gas pipe, for either gasoline or coal gas. 1. As a rule, the carburettor is located at the rear or side of the building to be lighted, and at a point somewhat lower than where the building stands. The location of the riser should be as near that of the carburettor as practicable, on an inside wall, and in that portion of the building that will allow the pipes to have a fall towards it with the least possible cutting of joists. 2. In large buildings it is sometimes difficult to get a fall to the pipes without considerable cutting of joists ; in such cases we recommend having two or more risers at different locations. 3. Keep the upper end of the riser, or tee, where you take off the connection for horizontal pipe, low enough to enable you to get the desired fall to all the pipe connecting into riser at that point. 4. All pipe in a building that is warm, and where joists have to be cut, should have a fall of at least ^ inch to the foot; in buildings or parts of buildings where the pipe is exposed and where it is not necessary to cut joists, the fall should be at least inch to the foot, but if it is con- venient to get more, it is all the better to have it, as you cannot get too much, especially in cold places. 5. If the building is so constructed as to make it impossible to have aH the pipes laid with a fall toward the riser, the pipes may be laid with a fall toward some convenient point and connected into a drip can, so the condensation will run into the can instead of into the riser. This can should, where possible, be placed outside of the building or in the cellar, and never in a place where it can be gotten at conveniently, excepting when necessary. 6. A stopcock must be put on the pipe before it is connected, so that the gas can be shut off from the can while it is being emptied. 7. Under no circumstances must there be any sags or traps in the pipe. Every inch of pipe must have a fall towards the main riser, and this must be determined by the use of a spirit level. Never depend on the joists or floors, as they are seldom level. A very good way to do is to put a piece of wood, the thickness of the fall the pipe is supposed to have in two feet, on the bottom of the level, two feet from one end, then you can run the level along the pipe and see that it is proper with but little trouble. 8. All pipe should be secured with gas-fitters' hooks in such a manner as to make it impossible for any portion of it to settle and form traps. 9. All drops must be taken from the side or top of main line of pipe, and run horizontally to location of drops. The drop must be securely screwed up, well stayed both at top and bottom of joists, hung plumb, and brought about three inches below bottom of joists; if centerpieces 96 Gas Piping and Gas Lighting are used, the drops will have to be longer, according to thickness of centerpiece. 10. All brackets must be supplied from the pipe in the floor below. Drop elbows should be securely fastened to wall to prevent turning when brackets are being put on. Where pipe is run on a brick wall, the brick should be chipped out to allow the pipe to be sunk in so the plaster will fully cover it. 11. Use white lead mixed with boiled oil for making joints, being very careful not to get so much of it in the fitting or on the pipe that when screwed together the lead will close up the opening. 12. Each piece of pipe should be looked into or blown through to see that the bore is clear. 13. No pipe should be laid on an outside wall or in exposed places. If impossible to avoid doing so, they should be well protected by boxing or wrapping. 14. No riser in any building should be less than one inch (inside) in diameter, and no pipe used in any portion of the building, even to supply one light, should be less than 0.375 incji. 15. The following table gives the proportionate sizes and lengths of pipe allowed by us to be run: Size of Pipe. Greatest Length Allowed. Greatest Kuniber of Lights. | inch 15 feet 3 i inch 20 feet 6 f inch 50 feet 12 1 inch 75 feet 25 1J inch 90 feet 75 H inch 125 feet 100 2 inch 150 feet 200 16. Where additions are made to piping, the connections for addi- tional outlets should in all cases be taken from pipe where the rule for sizes can be followed. 17. In buildings where there are prospects of adding burners to present number, the pipes put in should be of sufficient size to allow for all possible additions. 18. After all the pipe is in, it must be tested with at least five pounds air pressure. If there are any large leaks, either sandholes or splits, the defective piece must be taken out and replaced by a perfect one. If the leaks are very small, they may be repaired by caulking them, with the pressure on, using soapsuds to tell when leak is stopped, and then cement them. Cementing them without first caulking is useless and must not be done. CHAPTER X. PIPING FOR ACETYLENE GAS. SPEAKING generally, the piping of buildings for acetylene gas does not differ materially from the piping as done for coal or illuminating gas, except in one respect, namely in the sizes required for the pipes. As is well known, the burners used in acetylene gas-lighting are of much smaller capacity than ordinary gas burners; it is usual to use burners using from 0.5 to 0.7 cubic feet of gas per hour. It would, therefore, seem as if much smaller pipes were required for acetylene gas. On the other hand, the specific gravity of acetylene gas is much higher than that of coal gas, and this naturally should be taken into consideration in fixing upon the pipe sizes. The diameters of the gas mains and services for acetylene must be of such size that they will supply the maximum re- quired volumes of gas to the burners without the necessity of carrying an excessive pressure in the pipes. The flow of all gases through pipes is expressed by the well- known formula of Dr. W. Pole, established by him in 1852, in a paper on "The Motion of Fluids in Pipes," namely: Q =,780 J*L*jl ....... (1) s X I, in which I = length of pipe in feet, d = internal diameter of pipe in inches, h actuating pressure in inches of head of water, s = specific gravity of gas, air being = 1. Q = volume of gas delivered by pipe in cubic feet per hour. Or, if we express I in yards instead of feet, Q -1350

never to use a lighted candle for finding gas leaks. Where the pressure of air used in testing is heavy, the hiss- ing sound of the escaping air frequently indicates the place where the leak is. The Testing of Gas Pipes 105 If it is at a joint, or if a fitting is found to have a sandhole, a common practice is to use gas-fitters' cement to close up the leak, but this cannot meet approval. It is, in fact, bad advice, for cement should not be used at all in a gas-pipe system, for reasons given elsewhere in this book. Where the building is large, or has a great many stories, it is safer and easier to test the gas piping in sections, or by floors, and to repeat the test for the entire building only after having made sure that the sections are tight. In testing old work, it is much more difficult to find leaks^ because a good part of the piping is hidden or covered up, ^In such a case* it is best to test first the exposed piping wherever practicable, and after making sure that it is tight, to test the portions which are permanently out of sight. The Joslin indicator, manufactured in England, by William Sugg & Co., if fixed on the house side of the gas meter, on a by- pass, is a good telltale for indicating small leaks. A similar appliance is made by Muchall in Germany, l/ In occupied houses the fact that there are gas leaks may sometimes be discovered by putting the ear to the gas meters, all burners being of course turned off. A noise in the gas meter indicates a movement of the recording works inside of the meter, and consequently a passage of gas in other words, leaks either in pipes, fittings or fixtures. When the gas is turned on at the meter, it is best to use the nose in hunting for leaks. Some books on gas-fitting state that leaks may be found by " using a lighted taper in the search," but although they add that " great care must be exercised to guard against setting the building on fire," I am strongly opposed to such practice. At the point where the gas leaks, the open flame may ignite the gas, and cause it to burn, perhaps, with a very small bluish flame, which is either scarcely per- ceptible or which may be out of sight. The flame may finally set some woodwork on fire, particularly if the leak is in a closely confined place, in partitions or between floors. In other cases the mixture of gas and air may be such as to become explosive, and gas explosions may result. (See " Hints to Gas Consumers," Chapter XXI.) When one is satisfied that the gas-pipe system is tight, it is a good practice to have some of the caps on the outlets loosened on each of the floors, while the pressure is still kept on the 106 Gas Piping and Gas Lighting pipes. Care should be taken to have the cap loosened only sufficiently to indicate by the falling of the mercury in the gauge that the particular section of piping, which feeds the gas outlet selected, has been under test. The experiment also gives useful indications that the piping is not clogged up. Where the gas fixtures are hung by parties other than the man who did. the piping, it is a good plan for the gas-fitter to retest the pipes just before the fixtures are connected. If they are shown by the test to be tight, it necessarily follows that any subsequent gas leaks must be at or in the gas fixtures, and they will be found either at the gas keys, or the swing joints of folding brackets, or at the joint where the fixture is hung. In some cities in Europe, the tightness of a gas-pipe system is tested with the aid of a small gas-holder of 1 to 2 cubic feet contents, which can be loaded with weights up to a pressure of 3 pounds or 6 inches mercury. The gas-holder has a scale divided to one three-hundredths .of a cubic foot, and an escape of one six-hundredth to one nine-hundredth cubic foot can be readily measured. In applying the test, the gas-holder is con- nected with the pipes to be tested, and filled wit'h either air or illuminating gas. The sinking of the gas-holder, when the apparatus is connected with the gas pipes, indicates leaks, which are searched for as described above. In England, use is often made of " tell-tale meters," with which the smallest leak can be detected at the instrument. It is usual in this case to divide the piping in smaller sections. This test may be more accurate and scientific, but it is neither as simple nor as rapid as the test usually applied by American gas-fitters. It is difficult to fix upon a limit for allowable small leaks (no system of gas pipes being really absolutely gas-tight). When the gas-holder test is used, it is sometimes ruled that the hourly loss by leakage should not exceed one-thirtieth to one- fifteenth cubic foot per three hundred lineal feet of pipe. The following remarks, contributed by a practical gas-fitter to the columns of The Metal Worker are to the point : "If the mercury stands at a given height for from fifteen to twenty minutes with a round bead on top, and does this repeatedly, there is no leak that any man can find or detect with any appliance that I have knowledge of. I often have had my men report to me that the mercury, after standing some time, will rise if the atmosphere became warmer while they were The Testing of Gas Pipes 107 testing. Just so will it fall toward evening if it is pumped up during the afternoon or while the atmosphere is warm, which goes to show that the expansion or contraction of air in the pipe affects the mercury. "I once had a leak in a small gas job that two men worked faithfully for ten hours to find. The mercury would fall about & inch in fifteen minutes, showing that there was a very small leak. We could detect a slight smell of ether on a piece of f-inch pipe, 18 inches long. We lathered it, but could get no bubble. I turned the gas on it, but found that it would not burn through the hole. I had the pipe removed and a sound one put in. This did the work effectually, curing the leak and proving that a very slight leak will show on a mercury column in a short time. I afterward tested the defective piece of pipe, and under forty pounds water pressure it would sweat a drop about once a minute through a hole that you could not see." ! It is a good plan, in all large buildings, particularly in facto- ries, mercantile buildings, churches, theaters, and hospitals to have the gas pipes tested periodically, and at least once a year. To do this thoroughly, it is advisable to take off all the gas fixtures and to cap the outletsJ Where one does not care to go to this trouble, it is possibl^ to find out if there are leaks by watching closely the small index of the gas meter. (See Chapter XVII.) A great many small leaks usually exist at the fixture joints, at the gas keys, at the stuffing-box joints of chandeliers, and at the points where the lava tips are inserted in the burners. Leaky gas keys should be carefully reground, but, for the time being, a leak at a gas key may be stopped by applying a mixture of grease and beeswax. CHAPTER XII. GAS-LIGHT ILLUMINATION. THE chief means for obtaining a good and satisfactory illumi- nation by gas-light should be briefly mentioned. The term "gas lighting," or gas-light illumination, signifies the artificial illumination of interiors, and of streets, parks, and public squares, by means of gas flames or gas jets. In the houses, gas lighting is accomplished by means of more or less ornamental wall brackets and chandeliers, adapted for burning illuminating gas in burners or tips, arranged singly or in clusters. It is not intended to discuss in this book the illumination of streets and squares. It will be assumed: (a) That the gas supplied to the con- sumer is properly purified at the gas works, and that in quality it is of the requisite and sufficient candlepower. (6) That the gas piping in the building has been done in a first-class manner, and in accordance with the rules given in the preceding chapters; that pipes and fittings of proper materials and of ample size have been used; that these pipes and fittings have been put together in a workmanlike manner and are tightly jointed; that the distributing pipes have been properly run, with sufficient grade and with good fastenings and supports ; that all gas outlets have been securely strapped ; and that the piping has stood a severe pressure test and has no leaks or imperfections. (c) That the gas company has run a service of ample size into the premises, and has set a gas meter of sufficient capacity to supply all burners likely to be in use at one time. Under such conditions, the factors upon which the illumina- tion depends are the gas burners, the pressure regulators, the globes and globe holders, and the gas fixtures. The essential preliminary steps which gas consumers who desire a good illumination should take, are: (1) To select and use the best quality of gas burners, for these will not only give a better light, but they will burn less 108 Gas- Light Illumination 109 gas in proportion to the candlepower developed than poor burners, or, to put it in other words, they will produce a higher candlepower per unit of gas consumed. (2) To regulate the pressure with which the gas issues at the burner, which may be accomplished either by the use of gas- pressure regulators on the main house pipes for gas, or by using volumetric or governor burners at the gas fixtures. (3) To regulate the air supply to the flame, which is accom- plished by the use of suitably shaped and suitably placed gas globes, and in the case of Argand burners, by the use of well- proportioned glass chimneys. (4) By selecting well-designed and well-constructed gas fix- tures and judiciously placing the same in the apartments to be lighted. According to an elaborate report, made by the London Gas Referees, in 1870, a serious waste of gas occurs, owing to the great number of bad burners in general use. Consumers may, by using good instead of poor burners, obtain from thirty to fifty per cent more light without any increase in the gas bills. From this it is evident that gas may be used wastefully or economically, this depending largely on the selection of the burners. Burners suitable for ordinary coal gas are not adapted for gas of high candlepower, and vice versa. Unfortunately, the proper methods of burning gas are little understood, not so much owing to want of popular information on the subject as on account of the general indifference of the gas-consuming public as well as of the gas companies. Gas consumers are, as a rule, very slow in the adoption of progressive methods or appliances in domestic gas lighting, and the gas companies, with a few commendable exceptions, have not in the past made the slightest efforts in the interest of the consumers, by explaining in a lucid manner the problem of how to burn gas economically, and how a maximum efficiency of light, combined with perfect and complete combustion, may be obtained from the burning of a cubic foot of gas. Much remains to be accomplished in this direction; many widely existing fallacies regarding gas lighting have to be fought and removed, and in their place a correct knowledge of the principles of gas illumination should be disseminated. In by far too many cases, the existing conditions, such as too small pipes, meters of insufficient capacity, excess of pressure, bad 110 Gas Piping and Gas Lighting burners, ill-shaped globes, cumbersome globe holders, and defective gas fixtures preclude any chances of obtaining a suc- cessful illumination. I cannot here go into a consideration of the nature of the gas flame or into the theory of combustion, and will simply state as a general axiom that gas should be burnt at a low pressure. The most favorable pressure varies slightly with the quality, candlepower and specific gravity of the manufactured gas, but may be taken on an average as five-tenths of an inch of water pressure at the burner. An excessive high pressure of gas has a tendency to reduce the illuminating power of the gas flame, and it also causes the roaring or singing of flames, the flickering of the lights, the cracking of glass globes and a waste of gas. On the other hand, if the pressure is too low, the flame is apt to smoke, becomes dull and reddish in appearance, and vitiates the air. The art of illumination is practically a new science, and it is only recently that professional men have taken up the subject from a scientific as well as practical point of view. A large yet untrodden field is open to the new profession of the " illuminating engineer." Those in search of sound information on the subject would do well to obtain a copy of an excellent treatise, recently published, entitled "Practical Illumination,"* by Cravath and Lansingh, both authors being men who have devoted years of study and investigation to the subject. The monthly issues of a new magazine, called Illuminating Engi- neer, also contain important information. * Practical Illumination, by Cravath and Lansingh. McGraw Publishing Company, 1907. Price $3.00. See also the following six instructive pamphlets, issued by the Holo- phane Glass Company of New York City: Light vs. Illumination. The Lighting of the House. The Lighting of Large Buildings, Offices and Stores. The Lighting of Theaters and Public Halls. The Lighting of Churches, Schools, Libraries, and Hospitals. The Lighting of Hotels and Clubhouses. See also a pamphlet, issued by the Nernst Lamp Company, of Pitts- burg, in 1907, entitled The Art of Lighting, by Lux CHAPTER XIII. GAS BURNERS. A GAS BURNER may be defined as the point at which illumi- nating gas issues from the service pipe to be ignited for the purpose of giving light (or in some cases heat). A gas burner generally consists of a metal, lava, or steatite tip attached to the gas fixture, which by its size or opening regulates to some extent the size of the flame and the amount of the gas con- sumed. The common gas burners for lighting are generally composed of two parts, the body and the tip of the burner. Before mentioning in detail the different kinds of gas burners in common use, a few words should be said about the nature and the chemical process involved in what is known as the 4 'luminous flame." The process does not vary in principle whether the illuminant burned be solid (like the tallow, wax, paraffine, or other candles), or liquid (such as colza oil and kerosene burnt in lamps), or gaseous (coal or water gas). All gas contains hydrogen and carbon. In all illuminants the heat of the flame eliminates carbon; the hydrogen combines with the oxygen of the air, creating a very high temperature, which causes the carbon particles to become incandescent. The carbon is finally con- sumed in the flame, and carbon dioxide, some carbon monoxide, and watery vapor are formed. While in candle and oil-lamp illumination the gas is only generated during combustion, it is in the case of gas illumina- tion already prepared at the gas works and therefore issues at the burner ready to be lit. Every luminous flame has three distinct parts or zones, namely : an inner zone, where there is no combustion ; a middle or intermediate zone, in which partial combustion takes place, and which is the luminous or light-giving zone, as it contains the carbon particles raised to incandescence; and finally an outer zone where complete combustion takes place, and which is non-luminous. ill 112 Gas Piping and Gas Lighting The luminosity of a flame, of whatever nature, depends, therefore, first, upon the amount of carbon or light-giving sub- stance contained in the flame, and, second, upon the proper, sufficient, but not excessive air supply to the flame. Should there be too much air supply, the intensity of the flame will be reduced. The bluish or non-luminous flame of the Bunsen burner is due to the excess of air furnished to the flame. For this reason, gas should not issue at a burner under too high a pressure, for this causes too much air to come in contact with the flame. It is an axiom, which should be borne in mind, that in the flat-flame and Argand burners gas should be burned under a low pressure. In determining upon the kind and size of burners to use, one should take into consideration not only the amount of light, i.e., the candlepower desired, but also the gas pressure at the burner orifice and the specific gravity of the gas, or its proportion of hydrocarbons. The lighter the gas is, the more volume will flow out at a burner. Those gases which are rich in hydrocarbons have the smallest specific gravity but the highest illuminating power, hence require small burner openings; heavy gas, on the other hand, or gas which contains a lesser amount of hydrocarbons, requires to be burned in larger burners. Early in the history of gas lighting we find the energies of able inventors devoted to the improvement of the original and crude devices which had served as gas burners, but the correct principles, according to which a perfect gas flame was to be produced, were not then known. It is both interesting and instructive to follow the gradual developments of the better class of burners. Nearly a century after the invention of gas lighting a fresh impetus was given to the gas-burner industry by the introduction of the electric lamp. This compelled gas companies to devote attention to the available better gas ap- pliances for street illumination, and also caused consumers to make inquiries about the details of properly constructed gas burners for interior lighting. The London Gas Referees called attention to the fact that by the use of good burners 50 per cent more light without increased gas bills could be obtained. At the present day, the simplest as well as the most scientifically and accurately constructed gas burners are available, and new improvements are constantly being made. Gas Burners 113 Broadly speaking, we may distinguish between the following types of gas burners, viz. : (a) Single-jet burners. (b) Flat-flame burners: (1) Bat's wing. (2) Fish-tail. (c) Round-flame or Argand burners. (d) Multiple flat-flame burners. (e) Regenerative burners. (/) Incandescent burners: (1) Upright. (2) Inverted. Of all gas burners, the single-jet burner is the simplest, oldest, and crudest device, consisting of a plain body and 1^ip, generally combined, having only one small, round aperture for gas. These burners were used only to a limited extent, where a very small flame was required, and hence they may be dismissed with these few words. The second and third types of burners, viz.: the flat-flame and the round-flame burners, are those with which we were chiefly concerned in dwelling-house illumination until the inven- tion of the incandescent gas-burners brought about great and far-reaching changes. Of the two types named, the bulk of burners used belong to the flat-flame type. Ah 1 flat-flame burners, as the name implies, spread their flame in a thin, broad sheet. It is usual to distinguish two kinds of/ flat-flame burners, viz.: the bat's-wing or slit-union burner, and the union-jet or fish-tail burner. The bat's-wing burner has a hemispherical tip, with a narrow vertical slit, from which the gas issues in a thin and broad sheet, whereas the union-jet, originally invented by James Milne, of Edinburgh, consists of a flat and sometimes of a slightly depressed or concave tip, with two small holes drilled under a certain angle to each other, from which two jets of equal size issue, and by impinging upon one another produce a flat flame. Flat-flame burners do not require the use of a chimney to prevent the smoking of the flame, but the gas flame is usually sheltered against draft by surrounding it with a glass globe, except in the case of the imitation candle burners which, how- ever well they may look on gas chandeliers do not give a good illumination as they usually have very small tips, and also because they are apt to flicker. As originally constructed, the two burners produced flames widely differing in character, the bat's-wing burner giving a 114 Gas Piping and Gas Lighting flame of great width and little height, while the fish-tail burner produced a flame considerably narrower and longer. While the bat's-wing burner is better adapted for burning heavy gas, the fish-tail burner should be selected for gases rich in hydro- carbons. On account of its great width, the flame of an ordinary bat's- wing burner is easily affected by even slight currents of air, which cause the flame to smoke, and the protection which a glass globe affords to the flame cannot be so readily applied to the common bat's-wing burner, because the slightest lateral devi- ation of the broad flame often causes the cracking of a glass globe. This is one reason why ordinary union-jet burners are so commonly used on gas fixtures with glass globes, although the bat's-wing burner is slightly preferable, as regards the develop- ment of light. An early step in the improvement of flat-flame burners con- sisted in simple devices, intended to reduce the velocity with which gas issues at the burner orifice owing to the gas pressure, experiments having established the fact that a greater degree of illumination could be obtained by burning gas at a low pres- sure. These devices consisted in introducing some mechanical obstruction, such as wire gauze, cotton, wool, or a mica disk, or a regulating screw, into the body of the burner. Owing to the fact that coal gas is not always well purified, all devices which serve to constrict the lower part of the burner are very liable to stop up with tarry matters carried in suspension in the gas, which become condensed and are deposited in the wire gauze or in the wool. After some time, such "check burners," as they are sometimes called, generally become unfit for use, or at least produce a very ragged and uneven flame, owing to the material in the body of the burner becoming more obstructed in some parts than in others. The first valuable improvement in gas burners consisted in the selection of a more suitable material for the tip or head of the burner. The old burners were usually made entirely in one piece, either of iron or of brass. Movable tips were intro- duced later on, and were inserted in the metal body of the burner, but at first these tips were still made of iron. This material is objectionable for two reasons, viz. : first, the burner orifices in union-jet and in bat's-wing burners become rapidly choked by the corrosion of the metal. Such obstructions by Gas Burners 115 rust may, it is true,' be removed from time to time with burner cleaners, sold in hardware stores or obtainable from the gas companies, those for union-jet burners being in shape of a small awl, while those for slit burners consist of thin strips of sheet brass or steel, fastened to a suitable handle. The average householder rarely bothers himself with such matters; but even where these burner cleaners are used, the inevitable result of their too frequent or careless use will be that the burners quickly become injured or destroyed. The nickel plating of the iron burner tips obviates to some extent the corrosion of the burner orifice, and quite recently a non-corrosive aluminum gas tip has been put on the market, for which the advantage is claimed that it does not chip or crack, as lava tips sometimes do. A second and more important objection against brass or iron burner tips is that metal, being a good conductor, abstracts much heat from the burner tip, and thereby reduces the tem- perature of the flame, causing some loss in the degree of illumi- nation. Therefore, a great step forward was made by the introduc- tion of non-metallic, non-corrosive, and non-conducting sub- stances for burner tips. The material most commonly used is lava, but this is brittle and cracks easily, and various gas-burner manufacturers employ other materials, such as porcelain, or steatite (a sort of soapstone of very fine grain, which burned in a kiln becomes hard and incorrosive, and is easily polished) or "adamas," a compound artificial material of a mixture of various earths or minerals, or some sort of " enamel." Sugg's and Bronner's burners have steatite, Bray's burners enamel, and Leoni's burners adamas tips; and all modern improved flat-flame and round-flame burners have tips made of one or the other of these materials, which are practically everlasting and not susceptible of oxidation. Further improvements made relate to the shape of the tip and of the body of the burner. In some gas burners, for in- stance, the body is suitably enlarged to form a sort of expansion chamber wherein the velocity of the gas, as it issues from the pipe, is, to some extent, checked. The bat's-wing burner was improved by making the interior of the top of the burner hollow. The slit thereby becomes of equal depth throughout. Sugg also improved the bat's-wing burner by cutting the slit with a circular saw, which has a 116 Gas Piping and Gas Lighting favorable effect upon the shape of the flame. The advantage is thereby gained that gas issues more uniformly at all points of the tip, and the shape of the flame thus becomes improved, i.e., it is less broad and somewhat taller. A further improvement of the bat's-wing burner was made by William Sugg, who applied a rim-like projection to the out- side of the burner below the slit, a so-called " table-top," the object of which was to check the rush of the outer air in the immediate vicinity of the flame. Thus the flame is better protected from drafts, the shape of the flame is more evenly preserved, and all smoking is prevented. Manufacturers of union-jet burners, in turn, were not slow in applying improvements to their type of burner. Some introduced into the body of the burner layers of muslin to check the flow of gas, others inserted plugs or washers of enamel, perforated with small apertures for the passage of gas. These apertures can be adjusted to various pressures, and the ultimate object in view is to cause the gas to issue at the burner tip at the lowest pressure consistent with proper illumination. The result is that the height of the gas flame, which in the common fish-tail or union-jet burner is excessive, becomes considerably reduced and the roaring and flickering of the light is prevented. A similar result was obtained by making the burner top slightly hollow, and the angle at which the two streams of gas meet more obtuse. By all these improvements, the two at first quite different flames of the bat's-wing or slit burner, and of the union- jet or fish-tail burner, have been modified and gradually altered so much that in their modern and most improved form the shapes of the flames of the two types are practically identical. Among the best improved flat-flame burners are those of Broenner, Leoni, Sugg, Bray and Silber. The Sugg improved hollow-top steatite slit burner, the Sugg circular-slit table-top steatite burner, the Bray enamel non-corrosive "regulator" fish-tail and slit burners, and the Silber "Concordia" flat-flame burner, which has two small burner orifices separated by an intervening wedge-shaped piece of brass, are among the best ordinary flat-flame burners obtainable in the market. These burners are all of English make, except the Broenner burners, made in Frankfort-on-the-Main, Germany. Of the latter burner eleven numbers are made, consuming from one to eight Gas Burners 117 cubic feet of gas per hour. They give a uniform light with varying gas pressures, and if judiciously selected and fitted with the "Cornelian" globes with large bottom and top open- ing and a shadowless glass holder, as recommended by the manufacturers, they give a good and satisfactory illumination. I have not learned of any efforts on the part of American gas-fitting manufacturers to bring out improved flat-flame burners, comparable at all in efficiency with those above men- tioned. The mill burner with screw check, the " Empire" check burner with inside adjustable screw cylinder with slot, the " Imperial" burner with wire gauze to check the flow of gas, the Gregory mica-flap burners, and the " Young America" burner with small brass diaphragm pierced by minute holes, are gas burners of American make, and being in the nature of check burners are somewhat better than the ordinary kind. I shall, however, have occasion in another chapter, on governor burners, to mention some very excellent American flat-flame burners. In a dwelling house of average size a comparatively small number of burners are required, hence it will pay gas con- sumers to put on their fixtures only the best burners, whatever their price may be. Improved gas burners are also much preferable from a sanitary point of view, because there is less contamination of the atmosphere in a house. Regarding the size of the burners, I would say, wherever a dim light only is required, as in halls, passageways, and bath- rooms, two- or three-foot burners, and for bedrooms three- or four-foot burners, may be used ; but for the gas fixtures in the principal rooms large burners, consuming from five to six cubic feet of gas per hour are much to be preferred, and it should be borne in mind that for bright illumination a few large burners - under low pressure are preferable to a large number of small burners. Under all circumstances consumers should avoid making the mistake of procuring gas burners promiscuously from irresponsible agents, or from peddlers, and afterwards blaming the gas company for "poor light," or for exorbitant gas bills. Before leaving the flat-flame burners, I ought to mention - some automatic safety gas burners recently devised, the object V of which is to automatically shut off the gas supply, in case a gas 118 Gas Piping and Gas Lighting light is accidentally extinguished, or " blown out," or in case the gas key is inadvertently turned on. An American patented device of this kind has a wire protruding from the burner tip, and extending down to the bottom of the burner, where it comes in contact with a small valve. While the burner is cold the valve is closed, cutting off the gas supply. When a light is applied to the burner the wire becomes heated, expands, lengthens, and pushes the valve away from its seat, thereby admitting the gas to the burner tip. As soon as the flame is extinguished, the wire, by cooling, contracts and again cuts off the gas. A simple safety regulator burner is patented by Jahn, and manufactured by Frederick Lux, of Mannheim, Germany. These burners would seem to be specially adapted for hotels and lodging houses, where gas is often "blown out" by ignorant people, and they may prove successful in preventing suffocation, suicides, explosions, and other accidents due to escaping gas. I have devoted considerable space to the discussion of the ordinary flat-flame burners because, notwithstanding the Argand, regenerative, and incandescent burners, the flat-flame are usually the consumer's favorite burners, and because the bulk of illumi- nating gas used for lighting purposes is still burnt in bat's-wing and fish-tail burners. Further mention of flat-flame burners will be made in the discussion of governor burners. (See Chapter XIV.) I will now pass on to consider the round-flame or the so-called Argand burners. Argand or round-flame burners consist essentially of a hollow ring, connected with the gas tube and perforated on its upper surface with a series of fine holes, from which the gas issues, forming an annular, hollow, round flame. The Argand burner derives its name from its similarity with the Argand oil lamp, and like the latter always requires a glass chimney, properly proportioned in diameter and height, to induce a perfect com- bustion by increasing the air supply to the flame, and also to lessen its susceptibility to side drafts. The Argand burner gives a higher candlepower per unit of gas consumed than flat-flame burners, but it also develops a greater amount of objectionable heat. The original burners of this type were not constructed on scientific principles, no provision having been made in them for regulating the air supply to the flame Gas Burners 119 and what is equally important the pressure of gas, and hence these burners were liable to smoke. We are indebted for important improvements in this direc- tion to Mr. William Sugg, the well-known English manufac- turer of improved gas-lighting appliances. In his improved Argand burner, gas is delivered at a very low pressure ; the supply is distributed evenly throughout the entire ring of holes; the flame generated is of even and regular shape; the chimney, which is so essential to the round-flame burner, is properly proportioned in diameter and height, and the burner is made of "steatite" instead, as formerly, of metal, which abstracts too much heat from the flame. The Sugg " London" Argand burner, with twenty-four holes, has so many good qualities that it was selected by the London Gas Referees, in 1869, as the standard test burner for sixteen-candle gas. Further improvements were embodied in Sugg's "London" improved Argand governor burner, which developed a still better light from the gas consumed, and in which a regular and uniform supply of gas to the burner was insured by the use of either a steatite float or a leather diaphragm governor. An equally excellent Argand burner, with automatic gover- nor, is made by the Silber Light Company, of London, while of American round-flame burners I mention the "noiseless" Argand burner, made by the Gleason Manufacturing Company. , All these burners are much improved by the addition of the \ volumetric gas governor, which maintains a steady flow of gas ^ and regulates the pressure. Of this apparatus I have occasion to speak in the next chapter. The Siemens precision burner is an improved Argand burner, having a flat disk in the center of the flame, which causes the same to bulge out and tends to a more perfect combustion with increased luminosity of the round flame. This is similar in principle and construction to the metal button deflector placed over the air tube, as adopted in many of the modern improved central draft oil lamps. Similar modifications of the Argand burner are the Grand gas lamp, the Niagara Argand burner, the Royal Argand, the Gordon-Mitchell high-power gas lamp, with inverted annular burner, forming a small regenerative Argand burner, and the Morey incandescent gas burner. 120 Gas Piping and Gas Lighting In order to obtain increased illumination, duplex and multiple gas burners were invented. In the double, duplex, or "twin" flat-flame burner, two bat's-wing or sometimes two union-jet burners are placed together on the same body and set at a cer- tain angle to each other, so that the two flames are made to combine. A somewhat greater amount of light is developed thereby than by using the two flames separately, but the light is no better than that obtained through a large single burner. Such burners are used very rarely, but recently they have been revived for acetylene gas lighting. Multiple burners consist of several concentric rings of round burners, or else of a series of three, five, or more, flat-flame burners arranged in such a manner that from whatever point they are looked at, a flat side of the flame is exposed. Bray's high-power street-lamp burners belong to this class, as well as Sugg's "Walthamston" and "Taj" high-power lamps. They have been gotten up and used to some extent to obtain a brighter street illumination, but also for the lighting of stores and large halls. The street lanterns of this type are made stormproof, so that the flame is not affected by the wind, and are provided with milk-white glass at the top of the lantern for the purpose of reflecting the light downward. Multiple round-flame burn- ers have been adopted to a limited extent in lighthouse and street illumination, such as the Wigham multiple burner and the Germania double and triple concentric Argand burners. The "Shaw" reflector lamp is a regenerative multiple flat- flame burner, in which an attempt is made to superheat the gas before ignition. Halliday's "Clapton" lamps are similar in principle, and in the United States similar lamps largely used are the Gregory incandescent and the Gleason "Beacon" lamps. I will next consider the high-power or regenerative gas burn- ers. In all burners of this type the high temperature due to the combustion in the gas flame is directly utilized to raise the temperature of the gas before ignition, or of the air supply before combustion , or of both, the result being an intensified and more perfect combustion, and a vastly increased illumi- nating power. All regenerative lamps produce a higher effi- ciency of candlepower per cubic foot of gas consumed than is Gas Burners 121 secured by ordinary burners, the burners are economical in gas consumption, and the light produced is intense and steady. One of the first regenerative burners was the Siemens burner, invented by Friedr. Siemens in 1879. In its original form this burner is a round-flame burner, in which the flame burns around a central porcelain cylinder, over the top edge of which it turns. From this point the products of combustion pass downward through a central flue, and in their passage they heat a chamber through which the air passes upward, becoming highly heated by contact with the burning body. The products of combus- tion are then carried to the escape pipe by means of one or two side tubes. The first regenerative burner gave a very powerful light, but it was clumsy and inelegant in form and appearance; the shadow cast by the large Body of the burner was objectionable, and hence it did not find much favor for interior lighting, although it was extensively applied for the lighting of streets, squares and parks, and large halls. Regenerative gas lamps have since then been modified and constantly improved, and the Siemens inverted regenerative lamp is now manufactured in several different forms. The Lungren regenerative lamp, which resembles the Siemens, is practically an inverted Siemens lamp, in which the flame burns outward and upward around a central shell which it heats to a high temperature. The air supply enters above the flame by means of tubes extending across the escape flue, and passes down on both sides of the flame. The flame is enclosed in a clear glass bell, semi-globular in shape, which is supported by a hinged ring. Other regenerative lamps, some having the flame burning from the inside out and others from the outside towards the inside, and all similar in principle, but different in details of design and construction, are the improved Siemens, the Wen- ham, Bower, Clark, Grimston, Thorp, Gordon, Sugg, Bray, Brown's " Brilliant," Fullford, "Meteor," Butzke, Schiilke, Westphahl and Muchall lamps. For dwelling-house illumination regenerative lamps have, up to the present time, been used to a very limited extent only, although the fact that nearly all of these lamps are powerful ventilating agents and may be made to assist materially in the removal of the vitiated air of apartments, would seem to 122 Gas Piping and Gas Lighting recommend them particularly from a sanitary point of view. Their application has been largely confined to special cases, such as the lighting of large assembly halls, stores, and for lighting streets and squares, and wherever used they have proven to be very economical in gas consumption. The burners of regenerative lamps are somewhat complicated, require a nice adjustment, and are liable to clog up with deposits of carbon, and need, together with the enclosing glass globe, frequent clean- ing and attention. This, together with the high price of the Jamps, has also acted as a drawback against their general introduction. Among the latest regenerative gas lamps, especially adapted for interior lighting, I mention Sugg's patent "Cromartie" gas lamp. In these lamps u a special form of steatite burner is used inverted, with the object of retarding the motion of the carbon particles through the length of the flame, thus allowing sufficient time for the oxygen of the atmosphere to combine with the carbon of the gas in combustion. This arrangement produces an intensely white flame in the form of a camelia, diffusing a perfectly steady, white, shadowless light of great illuminating power." Each lamp is provided with a Sugg auto- matic leather diaphragm governor. These Cromartie lamps are made in two forms, either as ventilating or as non-venti- lating lamps. In the ventilating lamps the heat developed by the combustion of gas is not only carried away without enter- ing the room, but it is utilized to assist in educing heat or viti- ated air from the apartments. In the case of smoking rooms this arrangement is particularly effective, all smoke being rapidly conducted to the exterior. The air at the ceiling level is kept cool and pure, and furniture, pictures, and gilt frames are not subjected to damage. The Cromartie lamps are said by experts to produce very high results in candlepower, the quality of the light is said to be excellent, and as these lamps are gotten up in a variety of pleasing and artistic designs, shapes, and colors, they lend themselves admirably to decorative lighting. Mr. MacFie, gas engineer of the firm of Milne, Sons & MacFie, in a pr.per read at the annual meeting of the North British Association of Gas Manufacturers in Edinburgh, in 1891, has pointed out one notable feature of all regenerative lamps, namely, that they throw the light downwards where wanted, Gas Burners 123 whereas all flat-flame burners tend to light up the ceilings and upper parts of the walls. A further advance in the perfection of gas lighting was made by the invention of the incandescent gas burners. In these burners the flame is not luminous in itself, but its heat is uti- lized in raising to incandescence some refractory substance introduced into the burner. The latter is usually an atmos- pheric or Bunsen burner with bluish flame. The light -giving substance may be a basket of platinum, as in the Lewis burner; or a conical-shaped basket or network of magnesia, as in the Clamond lamp; or a row of finely-shaped, parallel, suspended rods of magnesia, such as is used in the Fahnejelm lamp; or finally a funnel-shaped wick or mantle of cotton treated chemi- cally with sulphate of zirconium, and other rare elements, such as yttrium, thorium, didymium, and lanthanium, as seen in the original Welsbach incandescent burner. The Clamond was, and the Welsbach incandescent gas lamp is, used to a very great extent in Europe, while the use of Wels- bach mantle lamps has also become very general in this country. The former is the invention of a Paris chemist, the latter of a Vienna chemist, Dr. Auer von Welsbach. After being first put on the market the Welsbach burner disappeared again, owing to various imperfections. But it afterwards reappeared', in much improved form, and since a few years there are numberless similar incandescent burners, like the Kern burner, the Yotto burner, the Lindsay lamp, and others. The Welsbach and other incandescent lamps are very excellent while the mantle is new, but the light deteriorates after some use and loses some of its intensity, and this is par- ticularly the case where the atmosphere carries much dust, which settles on the mantle, forming a sort of incrustation, which renders the light less incandescent and changes it from white to red. One objection to the Welsbach style of incan- descent lamp is that the cotton mantle is extremely delicate and readily breaks, also that the glass cylinders surrounding the filament crack at times, and in doing so break the mantle. As good mantles are expensive, the Welsbach lamp, although undoubtedly very economical in the use of gas, in the end some- times proves to be quite costly. Among its advantages are the 124 Gas Piping and Gas Lighting steadiness of its light, particularly when used with a volumetric governor, and the decreased radiation of heat as compared with other high-power gas lamps. The Welsbach incandescent lamps have for many years been adopted in European cities for street illumination, and quite recently street lamps in the United States were fitted with incandescent mantles, and very favorable results have been obtained as regards lighting power. In New York and Brooklyn all flat-flame street gas-lamps are now replaced by Welsbach burners. The latest modification of incandescent 'gas lighting, intro- duced in 1905, consists in the use of inverted burners. The inverted gas burners throw the light downward and hence do not cast shadows; the mantles are shorter and hence do not break quite so easily; the light given off is better and stronger, and the gas consumption is less. For these reasons the in- verted incandescent gas lamp has quickly proven successful, and its popularity is bound to increase. Quite recently, such lamps have been used in connection with the compressed-gas system for the illumination of railroad cars, both here and abroad, and the mantles seem to be but little affected by the vibration and jarring of the cars. Another modification of the incandescent-mantle burner is what is usually called an u air-hole burner," the chimneys hav- ing a number of holes to furnish air to the burner. The device seems to increase the luminosity of the mantle, and accordingly air-hole incandescent burners have become quite popular, and a number of such burners have been put on the market. In Europe self-lighting devices, and even self-lighting man- tles are used to a large extent. A number of these have been introduced and repeatedly tried here, but failure resulted in most cases. The composition of the water gas, so much used in American cities, has undoubtedly been one cause of the com- mercial failure of these devices. It is claimed that the gas used here does not contain sufficient hydrogen to make the device operate successfully. The foregoing description of gas burners would be incom- plete without a brief mention of the albo-carbon light, which Gas Burners 125 gives a much increased illumination and a very white, soft, and steady light, by the carburetting of the ordinary gas. This process consists in supplying to the ordinary gas, at the gas burner, a further amount of carbon illuminants. The enrich- ing solid carbon material is kept in a vessel combined with the gas fixture, and the heat of combustion of the gas flame is used to preheat the gas supply and to vaporize the carbon, which thus enriches the gas, and effects a saving in the gas consumption. The discomfort and feeling of oppression existing in rooms lighted with gas burners, and which is due to the heat created by the flames, to the products of incomplete combustion escaping into the air, and to the amount of watery vapor given off, has led to the invention of so-called "ventilating" gas burners. Among such burners may be mentioned the sunlight burner, a fixture with one or more concentric clusters of burners, placed near the ceiling. The clusters are placed under a ventilator, which is connected at its upper end with a ventilating duct leading either to the outer air or to some larger vertical vent duct or shaft. Some of the regenerative gas lamps already spoken of have such a vent duct, and cause an efficient venti- lation of the room. It is stated that a ventilating regenerative gas burner, using about 20 cubic feet of gas per hour, will remove not only its own products of combustion, but in addition about 5000 cubic feet per hour of vitiated air of a room. In large rooms of assembly, lighted by gas, it is imperative that either ventilating gas lamps be used, or that special venti- lating arrangements be provided at the ceiling to remove all injurious products of combustion. In the same way, it is true that no large gas heating or cook- ing stove, or gas water-heater should be used without thorough and sufficient means of ventilation. CHAPTER XIV. GAS-PRESSURE REGULATION. GAS governors may be defined as devices for regulating the flow of gas in a gas main, in a gas fixture, or in a gas burner. As we shall see in this chapter, such devices are beneficial in preventing wasteful gas consumption and in preventing the roaring of gas flames; we shall also learn that they are more useful and serviceable than the method of regulating the pres- sure at the meter stopcock or at the fixture gas key. It is a well-known fact that the gas pressure in the supply mains is constantly fluctuating, and that, at times and in cer- tain districts, it is greatly in excess of what is required for proper combustion at the burners. The burning of gas under too high pressure means a large waste of gas and a loss in illu- mination, amounting sometimes to from 33-50 per cent. Con- sumers are made aware of an excessive gas pressure by the roaring, hissing, or singing gas flames, by the jumping up of the flames and by other irregularities. The pressure of gas is measured by siphon or U-shaped glass gauges, filled with water, and provided with a scale of inches and tenths of inches. The pressure is always given in tenths of inches of a column of water. The gas pressure should be about -f-Q inch at the gas meter, and since the friction in the pipes would cause a loss of from T 2 5 to T 3 o inch, this would leave a pressure of ^ at the burner, which is about right for flat-flame and Argand burners, while incandescent burners require a little higher pressure. It is a popular fallacy that gas companies willfully put on a high pressure at the works in order to make the consumers' meters go faster. A moment's reflection ought to convince any fair-minded person that this is not the case. If the above supposition were true, the gas companies would be the losers in two ways, viz. : (1) A high pressure leads to a larger loss by leakage at the joints in the street mains, a loss usually estimated at from 126 Gas- Pressure Regulation 127 seven to ten per cent of the total gas output, but often largely in excess of this amount. (2) An excessive pressure would mean an increased con- sumption, or rather waste, of gas in all street lamps having ungoverned burners and not supplied through a meter, for which gas companies are paid a fixed sum per lamp per year. It is, nevertheless, true that it is impracticable for gas com- panies to maintain a constant pressure in the street mains. In a town of small extent, with absolutely level districts, and with centrally located gas works, a gas pressure of 10/10 inches of water in the mains would be ample to supply all consumers. Such conditions, however, are quite exceptional, and as a rule, owing to variations in levels of various districts, owing to vari- ous diameters of the gas-supply mains and submains, owing to the unavoidable friction in the pipes and the extreme distances to which gas has to be conducted from the works, the gas works are obliged to put on a high initial pressure in order to insure a sufficient supply to the most distant consumers and to those located in low-lying districts. Again, no matter how well the gas distributing pipes in a house may be proportioned and adjusted, it is impossible to maintain an even pressure at the gas burners, for the pressure in the house pipes and at the burners changes continually with the varying number of burners lit at one time in a dwelling, and also, and to a higher degree so, with the varying consumption in a street or in a district. These unavoidable fluctuations of pressure range from 10/10 to 40/10 inches of water pressure. The evils of high gas pressure have long been recognized, and efforts have been made to avoid the same. An excess of pressure at the gas burner means imperfect combustion, loss of illuminating power, vitiation of the atmosphere, blowing and hissing gas jets, and a wasteful use of gas. In speaking of burners, I have already stated that a high pressure and small burners are not to be recommended; that, on the contrary, ample volume of gas, issuing at a low pressure, from large burners, are desirable conditions for successful gas illumination. The following results of experiments, taken from an able paper by Mr. Butterworth, the general manager of the Columbus (0.) Gas Company, exhibit clearly the evil effect of over-pres- sure at the burner: 128 Gas Piping and Gas Lighting TABLES I. (A) Common 3-Cubic-Foot-per-Hour Burner Tip. Pressure 10/10 15/10 20/10 25/10 30/10 Consumption in cubic feet per hour 5.70 7.55 9.15 10.40 11.45 Candlepower 13.36 16.62 17.64 18.88 17.08 Candlepower per cu. ft. per hr. of gas consumed . . 2.344 2.201 1.917 1.815 1.492 (B) Common 5-Cubic-Foot-per-Hour Burner Tip. Pressure Consumption in cubic feet per hour 10/10 7.45 16.32 2.191 15/10 9.70 21.96 2.264 20/10 11.50 23.28 2.025 25/10 13.15 21.80 1.658 30/10 14.20 20.28 1.428 Candlepower Candlepower per cu. ft. per hour of gas consumed These experiments demonstrate the enormous waste of gas occurring with common burners, where no attempt is made to regulate the pressure. They also show that high pressure means a loss in candlepower; for, whereas the consumption of gas doubled, the efficiency of the burner decreased 57 per cent, for the 3-cubic-foot-per-hour burner, and 53 per cent for the 5-cubicrfoot-per-hour burner, showing a slight advantage in favor of the larger burner. There are various ways in which the gas pressure in the house pipes or at the burners may, up to a certain extent, be controlled and checked. One rough method consists in throt- tling the main gas-cock at the gas meter, and another in turning the gas keys at each fixture, i.e., at the burners. Some- times both methods are jointly used, the meter-cock control to cut down wider fluctuations of pressure and the burner key to effect a finer regulation. Such methods, however, are un- satisfactory and unreliable, because the control of pressure is not automatic, and because it would obviously be impracticable to require the consumers to devote care, time, and almost constant attention to the frequent manipulation and adjustment of the burner keys, made necessary by the constant fluctuations in the pressure. Indeed, this would prove to be such a trouble- some and annoying proceeding that it would be likely to be overlooked or forgotten. Gas-Pressure Regulation 129 A multitude of check burners have been devised, all having in view a retardation of the velocity with which gas escapes at the burners. This they accomplish to a certain extent, but as the obstructing material is, as a rule, fixed in the burner and cannot be adjusted, whereas the pressure fluctuates con- stantly, it is obvious that check burners can not and do not attempt to regulate the flow of gas or govern the pressure. Even the best check burners, having adjustable checks, would require a frequent adjustment during the evening hours and, therefore, would have no advantage over the simpler method of checking the flow by turning the gas keys. All that can really be said in favor of check burners is that they are better than the common gas burners and that they are somewhat cheaper than automatic governor burners. The Empire burner, the Young America, the Broenner, Leoni, and Bray burners, Sugg's "Winsor" burner, Gregory's mica-check burner, and Silber's bat's-wing burner, having a lower chamber in which the gas expands and thus escapes at the slit of the burner tip under diminished pressure, are examples of this class. From Mr. Butterworth's paper I quote again two tests of consumption and efficiency, made with a 5-cubic-foot-per-hour Empire check burner and a No. 6 Bray special burner: TABLES II. (C) 5-Cubic-Foot-per-Hpur Empire Check Burner. Pressure 10/10 3.10 9.24 2.981 15/10 4.05 12.44 3.071 20/10 4.85 15.18 3.129 25/10 5.50 16.74 3.044 30/10 6.05 18.04 2.982 Consumption in cubic feet per hour Candlepower Candlepower per cu. ft. per hour ... . . (D) No. 6 I ray Specia 1 Burner. Pressure Consumption in cubic feet per hour .... 10/10 6 10 15/10 7 75 20/10 9 10 25/10 10 25 30/10 Candlepower ... 15 60 18 56 20 74 22 72 Candlepower per cu. ft. per hour . . 2 557 2 395 2 279 2 216 It is evident from the above observations that check burn- ers do not prevent wasteful use of gas, that they do not control 130 Gas Piping and Gas Lighting gas pressure, and that the gas consumption of check burners necessarily varies with the pressure. In the above tests the consumption of the Empire burner was nearly doubled when the pressure increased from 10/10 to 30/10, whereas the candle- power per unit of gas consumption remained the same. While the gas works may, by using station and district gov- ernors, reduce, or control to a certain extent, the pressure in the street mains, it is obviously desirable that the consumers should use means in their houses for controlling the gas pres- sure automatically. Gas companies long ago recognized the evils of excessive pressure, and also the fact that economy in lighting depends upon its efficient control. Where they under- take to furnish public illumination of streets and squares by contract with the city for a stated fixed annual sum of money for each street lamp, they, therefore, applied to the burners auto- matic means for controlling the pressure and thus preventing waste of gas. Two efficient methods, each one of them only applicable under certain conditions, may be adopted by the consumer to effect an automatic control of the gas pressure; gas governors are accordingly of two entirely different kinds. One may apply an automatic gas governor on the house service-pipe at the meter, which will regulate and reduce the pressure in the whole house-pipe system, and maintain a practically constant pressure at the level of the meter, or else one may use auto- matic gas governor burners, which control the rate of gas supply to each burner separately, establishing a constant con- sumption at each burner, while leaving the full pressure in the house pipes. By the use of governor burners higher results are attained in pressure regulation than by the use of pressure regulators. There are a large number of gas-pressure regulators in the market, and as it is the chief object of this chapter to point out to the consumer that there are means available for effi- cient control of the gas pressure, rather than to offer a detailed description of these devices, many of which are quite similar in principle and in construction, I will simply state that there are two kinds of pressure regulators, namely, the dry and the wet regulators, the former using a leather diaphragm, whereas the latter uses a float, cup or bell, dipping either in glycerine or else in mercury. Gas-Pressure Regulation 131 The Sugg and the Peebles diaphragm pressure regulators are examples of English devices of the first class, whereas the Scott, Shaw, Sugg, Bower, Ewart, Brown's "Excelsior" and Peebles' mercury, are English pressure regulators belonging to the second class. The " National" automatic and the Amick gas regulators are American liquid governors, having a brass globe floating in a seal of glycerine, and the Beattie, O'Gorman, and Patterson regulators are examples of American mercury-seal regulators. Some of these are obtainable for sale, whereas others are only placed on a rental basis in the houses of consumers by com- panies obtaining a revenue from the saving effected as shown by the monthly gas bills. It is an essential condition, where pressure regulators are applied, that the house pipes be made very ample in size, that there be as few elbows or bends in the pipes as possible, and that the tubing of gas fixtures, the aperture of gas keys, and the slits of the burners be large; in other words, that the volume of gas supplied to the burners be ample, otherwise the inevi- table result of a control of pressure is a loss of light, or reduced illumination. Therefore, such pressure regulators should never be used by consumers where the above conditions are not com- plied with, otherwise the remedy might prove worse than the evil complained of. It is equally useless to apply pressure regulators to houses in low-lying districts where the pressure is already low. In all cases the saving in gas consumption, which is the result of a reduction in gas pressure, should be effected without any loss of illuminating power. A pressure governor or regulator placed on the service pipe of a house reduces an excessive gas pressure and secures a toler- able uniformity of pressure and supply at all burners; but this is only true of buildings with small floor area and of few stories in height. For large factories and halls, with many lamps on the same level, where the whole number is always lighted, a pressure regulator will answer. In the case of large buildings and in all buildings of many stories, on the other hand, an absolutely uniform pressure is not attained, because no matter how well the distribution pipe system may have been calculated and arranged, there is neces- sarily some loss of pressure through friction in long pipes and at elbows, so that the gas at burners situated at a distance flows 132 Gas Piping and Gas Lighting at a lower pressure. Owing to its specific gravity, which is not quite one-half that of air (about 0.45), gas tends to gain in pressure with increased elevation, each rise of ten feet verti- cally adding one-tenth inch of water pressure. If the governor is adjusted so as to give a pressure of 6/10 inches on the ground floor, the pressure on a floor ten feet higher would be 7/10 inches and so on. This explains why, in high buildings, even with a pressure regulator at the meter, the gas pressure increases for each floor, causing the burners in the upper stories to "blow." Therefore, the better method in such cases is to provide a governor on each floor. It is sometimes feasible in cases where the number of burners lighted remains constant, and where the pressure varies only slightly, to control and reduce the pressure on each floor level by a governor, and in addition to use a good check burner at the fixtures. Sugg's "Winsor" screw-regulating burner has been devised with this special object in view. The best and surest remedy, undoubtedly, consists in the use of automatically acting governor burners at all fixtures. Gover- nor * burners must not be confounded with check burners, which only retard, whereas governor burners regulate, the flow of gas in such a way that, as the pressure increases, their regulating action increases, and vice versa. Such governor burners cause the gas to issue at the burner in a constant volume, no matter what the pressure in the service pipe may be, hence the name "volumetric" burners is sometimes applied to them. The first automatic regulating burners were devised for street lamps, and they were sometimes very clumsy in shape, casting large shadows downward. They have been much improved of late years, and now there are several good gover- nor burners obtainable which are compact in shape, not un- sightly on the gas fixture, and which act almost perfectly in regulating the supply to the burners, and in preventing gas from flowing out under excessive pressure. Even governor burners, however, may in time clog up, and will require occa- sional cleaning. There are many different makes of volumetric burners, and it is not my intention to describe any of them in detail. Briefly stated, the flow of gas is controlled in them by a light cup, cone, or disk, placed in an enlarged chamber of the burner, Gas-Pressure Regulation 133 which floats up or down as the gas pressure increases or dimin- ishes, and being connected with a valve at the entrance to the burner, it opens or closes the same, and thus causes more gas to be admitted when the pressure falls, and when the pressure rises reduces the supply. Volumetric governor burners are equally applicable to flat- flame, round-flame, regenerative, and incandescent burners. The best regenerative lamps are always fitted up with such a regulator, and likewise are the Argand and flat-flame burner lamps of the highest make always sold with them. Among the best-known governor burners I mention those of Giroud, Wilder, Sugg, Peebles and Lux, the first one being a French burner, the second a burner of American make, the third of English, the fourth of Scotch make, and the last one being a German volumetric burner. Other burners, not so well known or extensively used, are the Rappleys rheometric governor burner, endorsed in 1882 by the Committee on Science and Arts of the Franklin Institute; the Champion burner, patented by Van Wies in 1890; the Chamberlain, Boore and Jackson burners, all of American make; the Schuelke adjustable gas governor burner, of German make; and the Orme, Hawkins and Acme burners, of English make the Hawkins burner, being the only governor burner with union jet tip known to me. My list does not pretend to be exhaustive, and it is quite possible that I may have unintentionally omitted some good burners which have not come to my notice. The Wilder volumetric governor burner is the invention of Moses G. Wilder, M.E., of Philadelphia, who obtained a patent for it in 1880. This burner is a good example of an American governor burner, and it is suitable not only for flat-flame and Argand burners, but also for regenerative lamps and for the Welsbach incandescent lamp. The maker, in describing it, states that it is not a pressure reducer or regulator, that the flow of gas through it is not changed by very wide variations of pressure, and that it secures a uniform rate of supply to the burner, with little or no reduction of pressure. The inventor of the Boore burner, Mr. Lewis Boore, of Buffalo, N. Y., states that he endeavored to produce a reliable and simple automatic governor burner of low cost, which would indicate practically correctly for a very wide range of pressure, 134 Gas Piping and Gas Lighting without having such an extreme accuracy or such close adjust- ment as to destroy its utility. William Sugg & Co. make two kinds of volumetric burners, a steatite float governor and a leather diaphragm governor burner. Sugg's patent u Alexandra" governor burners combine great economy with efficiency, and produce a brilliant, white, silent light. They are fitted with steatite float governor, and the superior light attained is also a result of adopting double an- nealed Albatrine globes with wide opening. An even better flat-flame burner by the same maker is Sugg's patent "Chris- tiania" governor burner, fitted with a specially prepared leather diaphragm governor, with Sugg's patent table-top, circular-slit, steatite burner tip. Sugg's London improved Argand burner always has a governor burner attached to the fixture. Mr. Wilder calls attention to the fact that his governor burner, to operate well, requires a full street pressure. This rule is applicable to all volumetric burners; hence, where these are used, a pressure regulator should not be used at the meter. In order to show, by actual experiments, how nearly uniform the consumption of gas remains with governor burners, I refer the reader again to Mr. Butterworth's able paper on governor burners, wherein is published the following table, showing the gas consumption of a number of such burners under varying pressures : TABLE III. Pressure. 10 10 Cu. Ft. per Hr. 15 10 Cu. Ft. per Hr. 6.20 6.50 4.50 4.65 4.95 5.50 5.97 4.95 20 10 25 10 30 10 35 10 Cu. Ft. per Hr. 40 10 Cu. Ft. per Hr. Type and Make of Burner. Cu. Ft. per Hr. 6.35 6.20 4.55 4.55 4.95 5.40 5.21 4.95 Cu. Ft. per Hr. 6.30 6.20 4.55 4.65 4.95 5.30 6.19 4.95 Cu. Ft. per Hr. 6.25 6.05 4.65 4.70 4.90 5.07 6.05 4.95 6 cu. ft. per hr. governor burner 6 cu. ft. per hr. governor burner 5 cu. ft. per hr. governor burner 6.20 5.95 4.50 4.50 4.90 5.60 4.96 4.95 6.25 6.15 4.65 4.65 4.90 4.80 5.89 4.95 6.40 6.05 4.60 4.55 4.90 4.60 5.69 4.95 Sugg Peebles Chamberlain Rapplye Lux Champion Boore Wilder 5 cu. ft. per hr. governor burner 5 cu. ft. per hr. governor burner Adjustable burner . . Adjustable burner . . Adjustable burner . . Gas-Pressure Regulation 135 The last burner in the table showed a perfect uniformity of supply under the wide range of pressures used in the test. Some of these governor burners are adjustable, and if they are required to pass a certain quantity of gas per hour, a nice adjust- ment is necessary, which can only be accomplished if the candlepower and quality of gas, its pressure and specific gravity are known. A governor burner, adjusted for a gas of certain specific gravity, would not remain correct for a gas of different density, or for any temperature which would change the density. Both the pressure regulators on the main service pipe and the governor burners render the gas-piping system independent of the unavoidable fluctuations of pressure in the street mains and accomplish a saving in gas consumption by preventing useless waste, amounting to a reduction of from twenty to forty per cent in the gas bills. Other incidental advantages gained are : A great improvement in the steadiness of a gas flame without regard to the number of burners lit or the con- stantly changing street pressure; the hissing or roaring noise, the blowing, and the flickering of the light is prevented; the illumination becomes stronger; the smoking of Argand burn- ers is prevented, and the air of the room is vitiated to a much smaller extent by the products of imperfect combustion. With governor burners, however, these results are attained in a higher -degree than with pressure regulators on the service pipe. All efficiently-acting gas governors should effect a saving in the consumption of gas without causing a diminution in the light. In New York State the Legislature quite recently limited the maximum pressure of gas in the mains to that due to f| -inches of a water column. While this law aims at correcting the evils of too heavy gas pressure, it is doubtful whether it is desirable to control the pressure in this way. It might have the undesirable effect that in some districts or streets con- sumers would suffer from lack of pressure and lack of a sufficient supply of gas. While trying to comply, as far as possible, with the laws, the gas companies received hundreds of complaints daily that gas ranges would not burn properly, and that gas flames, left partly turned down, went out on account of lack of a gas supply. As already mentioned, gas companies, in order to avoid ex- cessive gas leakage in the street main, carry only a pressure 136 Gas Piping and Gas Lighting at the works sufficient for efficient service, hence this question could well be left to their judgment. In many city districts, which have grown beyond anticipation, or where numerous high buildings are located closely together, the old gas street mains have become inadequate for the service to be performed, and hence a higher initial pressure must be put on to force sufficient gas through the pipes. A possible solution of the difficulty might be found in a division of a city into zones or districts, each district being provided with a suitable automatic pressure governor. To sum up, practical considerations must decide which form of regulation it is best to adopt. In this connection the fol- lowing rules are to be recommended, viz. : (a) Where the street mains are large and the differences of level insignificant, use either check burners or volumetric burners. (6) Where the street mains are small, or the pressure is low, or the house pipes insufficient in size, neither method of regu- lation should be employed, and the only remedy would be to put in not only large burners, but also large pipes. (c) Where the town is hilly and there are reasonably large differences of elevation in the districts, a pressure regulator will answer in districts on a higher level than the gas works, provided the house pipes are large, the gas keys full bore, and the building only a few stories in height, and not of great extent laterally. (d) Where in such districts the buildings are high or very large, a pressure regulator on each floor should be used, to- gether with regulating check burners at the fixtures, but in such cases governor burners at the fixtures are a simpler remedy, and are, therefore, to be preferred. (e) Never use gas pressure governors where the gas pressure is low, or where the house gas pipes are known to be insufficient in size in proportion to the gas consumption, as the results would be very unsatisfactory. (/) Do not use gas pressure regulators on the main service where incandescent mantle burners are used, for these require a higher pressure than flat-flame burners. (, 3 c i 1 i i 1 Total. ^ rj o. W OJ 3 S ^5 & fc H^ & Dusk to " 9 o'clock 13 71 82 124 152 173 158 117 93 58 29 8 1078 "10 o'clock 44 102 112 155 182 204 189 145 124 88 60 38 1443 "11 o'clock 75 133 142 186 212 235 220 173 155 118 91 68 1808 "12 o'clock 106 164 172 217 242 266 251 201 186 148 122 98 2173 All night 217 307 345 421 473 527 512 411 382 295 242 195 4327 II. YEARLY TABLE OF GAS-BURNING HOURS. (From American Meter Company's Pocket book.) Number of Hours from Sunset to 10 P.M., with Average for Each Month. Average Daily Num- ber of Hours. Comparative Length of Evenings. June Hrs. Min. 76 55 Hrs. Min. 2 34 100 July May . . 83 52 88 38 2 42 2 51 109 115 August April . . September March . . February October . November January . December 99 16 102 47 115 24 127 06 132 59 140 14 153 35 163 16 168 25 3 12 3 25 3 51 4 06 4 25 4 31 5 07 5 16 5 24 132 134 150 165 172 182 199 212 218 212 Gas Piping and Gas Lighting Precautions to Render Gas Lighting Safe from the Danger of Fire. 17.' The majority of dwelling-house fires are due to defective or improperly managed lighting and heating apparatus. Both fires and gas explosions may result in consequence of leaky gas pipes. Hence make sure that all gas piping is absolutely tight, and do not permit even the smallest leaks to remain unattended. Do not permit the search for a leak with an open light, a taper, candle, or even a match. The escaping gas may become ignited without your noticing it. This in turn may set woodwork on fire. Some of the fires, the origin of which remains a mystery, may be attributed to this cause. Electric candles are much the safest devices to use in locating gas leaks. 18. Consider carefully the location of the gas fixtures. Swing- ing gas brackets are particularly dangerous, and often set wood- work of doors or windows, or curtains, portieres, shades, or wall shelves on fire. The remedy consists in protecting the open flame with a wire cage of large diameter, or in using stiff brackets in such places. Unguarded, open gas flames in a building are always dangerous and should be carefully watched at all times, and kept away from inflammable material. Gas flames should not be nearer to a ceiling than three feet, otherwise use some form of protection, either a metal or glass shield, a bell hung over the flame, a deflector or a ventilating hood. 19. In case of regenerative or other ventilating gas burners, the exhaust flues must be of metal, and should not be in direct contact with woodwork. 20. Glass shades or globes should be used to protect open flames from drafts. Wire cages are particularly necessary in the servants' department of a house; in the cellar, basement, and attic; in the laundry, the ironing room, the linen and storage closets. 21. Use only metallic reflectors; paper or pasteboard reflectors or shades are dangerous to use. 22. The very common practice of using rubber hose of any kind for the connections between a gas outlet and a gas stove, radiator, cooking plate, or even for a drop fixture is very dangerous. The cheaper grades of hose soon deteriorate in use, become leaky and are easily inflammable. Metallic hose is infinitely better though more expensive. 23. A stiff iron pipe connection between the gas supply and Practical Hints for Gas Consumers 213 the gas fixture is much more preferable and safe. It should always have a stopcock or valve to control the supply of gas. 24. Fires have been caused by the setting up of small gas cookers or laundry iron heaters on a wooden bench or table. The better way is to line the tables so used with bright tin. 25. Great care must always be observed in the use of matches. They not infrequently cause a fire if they are thrown away carelessly while still glowing. Always put burnt matches into earthen or metal receptacles. Keep fresh matches away from mice and rats. Do not leave matches exposed to the sun's rays. Wax and parlor matches are more dangerous in use than the so-called Swedish or safety matches. 26. In all large buildings the lighting up should be in charge of a special responsible man. He should be instructed to use care in the means for lighting the gas flames. He should not be permitted to use alcohol torches as they are dangerous for indoor use; electric torches or lighters are much better. 27. Broken or cracked lava burner tips in combination with a sudden increase in the gas pressure may cause a gas flame to flare up unduly and sometimes ignite nearby woodwork. Sudden changes in gas pressure are very undesirable in this respect. See that the gas meter is located in a ventilated place, which, if practicable, should be open to the outer air. Asphyxiation by Illuminating Gas. 28. It is a dangerous practice to accustom oneself to sleep in an unventilated chamber with the gas left burning low. A reduction in the gas pressure, which may happen at any time of the night, may cause the light to go out. If, later on, the gas pressure again becomes stronger,' the gas will escape from the open burner, gradually fill the room and endanger the life of the occupant. 29. Carbon oxide, which is colorless, odorless, tasteless, and very poisonous, is the constituent of gas which causes asphyxia- tion. It begins by causing a ringing in the ears, headache, dizziness, heart palpitation, drowsiness, confusion of the mind, lowering of the pulse, loss of feeling in the extremities, and finally loss of consciousness. As a rule, the person so exposed is unconscious of any danger. 30. Haemoglobin is the scientific name of the red coloring matter in the blood ; this normally absorbs oxygen from the air 214 Gas Piping and Gas Lighting which enters the lungs while breathing. The poisonous carbonic oxide has a greater affinity for the haemoglobin than the oxygen. Asphyxiation results because the carbon oxide renders the haemoglobin incapable of taking up oxygen in the lungs. 31. Persons who have been exposed to carbonic oxide should be removed to the open air; their clothing should be opened, and breathing should be restored by artificial respiration move- ments. Rubbing the person with warm cloths, and applying electricity are also useful. 32. Make it a rule never to neglect even the slightest gas leak. While the smell of gas sometimes gives a warning, it does not do so where gas has been filtered through the soil, and thereby has lost its odor. All such gas leaks constitute grave dangers to health, as well as fire hazards. This danger became more serious at the time when gas companies began the manufacture of the cheaper water gas, having about 30 per cent of CO, and abandoned the making of coal gas, which had only from 6 to 7 per cent CO. 33. Accidents with gas arise in general in one of the following ways: (1) By suffocation, as in the case of workmen working in trenches of broken or leaky gas mains. (2) By the formation of an explosive mixture of gas and air. (3) By asphyxiation during sleep, when gas escapes from a burner or from defective fixtures; asphyxiation is often due to ignorance in gas matters; in some cases it is due to accident, in others to intention. (4) By slow and obscure poisoning caused by the cumulative effect of a number of small leaks in the house pipes. (5) By gas escapes from broken street mains into the soil, thence into cellars of houses, and up through the house. These cases are particularly frequent and dangerous in winter time. Such accidents can even occur in such houses which have no gas supply whatever. The soil is apt to absorb the odor of the gas and becomes impregnated by it, whereas the escaping gas itself loses its peculiar odor. Gas Consumers' Complaints. 34. Consumers' complaints may be summed up as follows: (1) The gas pressure is insufficient. (2) The gas pressure is too high. Practical Hints for Gas Consumers 215 (3) The quality of the light is bad; there is less light than formerly. (4) The gas flames burn irregularly or jump. (5) The gas bill is much higher, although no more gas than formerly is burnt. 35. Gas should, of course, always be supplied by the company to the consumers under a sufficient pressure to give a maximum of illumination, or, where gas is used as fuel, to give a maximum calorific effect. Consumers should remember that a moderate pressure of gas and a burner of large size give the best results. They should also take into consideration that different kinds of gas burners require different pressures; thus an Argand burner requires less pressure than a flat-flame burner; this in turn requires less pressure than an incandescent burner; the greatest pressure is required at cooking burners and heating stoves. 36. Insufficient gas pressure is generally due to local causes, such as too small piping ; piping partly stopped up with rust, tarry matter or naphthaline ; gas meter of insufficient size ; service pipe obstructed and requiring cleaning out. 37. The increasing number of complaints of loss of light is largely due to the fact that builders furnish buildings with defective, inferior, and inefficient gas-fittings. In many build- ings, even in modern and new ones, and not merely in houses erected by the speculative builder, but also in those of a higher grade and selling at high prices, the gas piping is improperly done, and the pipes throughout are too small, causing a loss of pressure in the system. Thus it happens that the gas company, or sometimes the manufacturers of gas fixtures, receive blame for poor illumination, when the trouble is really due to the bad piping done by the builder or his gas-fitter or plumber. 38. In a few cases the trouble with the illumination is due to the gas company's fittings, which comprise, as we have seen, the service pipe and the meter. The sendee pipe may be too small, and in other cases the meter may be of insufficient capacity. The gas company usually will remedy both defects promptly if notified, and it is not often that gas companies deny an appli- cation for a larger meter. 39. The most common fault is the insufficient size of the house pipes for gas. One frequent cause deserves special mention, i.e., the supplying of a gas log, a gas fireplace heater, or even of a 216 Gas Piping and Gas Lighting gas range from the same riser which feeds the lamps. Gas fires and gas cooking stoves are often installed and supplied from services originally intended for only a few flat-flame burners. The gas fires are often used simultaneously with the lamps. In other houses, gas flames giving only a dismal illumination jump up suddenly to a satisfactory brilliancy when some of the burners are turned off. This conclusively shows that the house piping is insufficient in size, and the remedy is, of course, to put in larger pipes. But the consumer or the house owner may be shy to apply the only right remedy, because it involves a good deal of tearing up of floors and ceilings as well as the cutting of plastering. And so, rather than cure the evil, the consumer goes on grumbling about his poor light. 40. There are many cases where the same gas, used in a num- ber of adjoining houses, produces in one house a good illumi- nation, whereas the adjoining house may suffer from poor light. In such case the conclusion is unavoidable that the quality of the gas furnished by the company cannot be at fault, and that the whole trouble must necessarily be in the system of gas piping or in the burners of the badly-lighted-up house. 41. Irregular or jumping gas flames are nearly always due to local causes, such as the accumulation of water either in the gas meter, or in some low and defectively-run piping in the house. 42. Troubles with poor light are not always due to insufficient size of house pipes, or to partly-stopped-up pipes, or to too many fixtures being taken off from one riser, or to an obstructed service. There are numerous cases where a street gas-main has outgrown its usefulness in consequence of a sudden increase in the number of gas consumers in the district which the main supplies. In such a case, the remedy should be applied by the gas company, and consists in replacing the street main by one of larger capacity or else in putting in an additional main. 43. The above explanations will suffice to indicate that it is unwise and usually wrong, for consumers to jump at the con- clusion that the quality of gas supplied by the gas company is inferior. There may be and there usually are other reasons for the consumers' complaints. " A gas company may in all sincerity send out gas of even better quality than standard, yet be accused of supplying Practical Hints for Gas Consumers 217 1 bad gas ' ' (London Journal of Gas Lighting). To assume, as many consumers do, that the gas companies persistently violate the requirement of a standard quality of gas is erroneous and unwarranted; for all manufactured gas is frequently tested by official municipal inspectors. As a matter of fact, the records of testing stations show that the gas seldom falls below the stand- ard requirements. 44. To explain the fact that gas consumers quite often obtain a very unsatisfactory supply of gas, which fact is true beyond doubt, it is necessary to look to other causes, such as those mentioned above, to explain it. 45. Consumers who wish to have a good illumination should avoid cheap gas fixtures and cheap gas burners; they should use only the best burners and efficient globes or shades. They should also remember that the modern higher require- ments regarding the illumination of interiors are at the present time fulfilled in the best manner by the use of the incandescent gas lamps. A Word to the Gas Consumer about the Price of Gas. 46. A mistake too frequently committed by the gas consumer is to judge the cost of gas by the price charged per one thousand cubic feet, without considering the candlepower of the gas. Without a knowledge of the latter, it is really impossible to tell whether a gas is cheap or expensive. Gas at $1.00 per 1000 cubic feet, and giving 16 candlepower is actually dearer than gas of 22 candlepower at $1.25. Burnt in a 5-cubic-foot-per hour, flat-flame burner, the former gas costs 3.12 cents per 100- candlepower-hour, whereas the latter costs 2.84 cents. 47. High candlepower gas is only needed for flat -flame and Argand burners; it is no longer required where incandescent mantle burners are used. In fact, a gas of low candlepower, so burned, gives better results than a high candlepower gas. 48. Speaking of the price of gas, the London Journal of Gas Lighting says: "The public generally resents more strongly an increase in the price of gas than a proportionate or even a greater rise in the price of other commodities. So many people speak as though they were the victims rather than the customers of their gas company, as though, in fact, they got nothing for their money, that it seems clear that this idea, carefully fostered 218 Gas Piping and Gas Lighting by the so-called comic paper, with its antique gibes at the accu- racy of the gas meter, lies at the root of much of the hostility sometimes displayed towards gas undertakings." 49. The question, so frequently asked by gas consumers, appears justified: "Why are the gas bills higher at present than in former years, for the same number of fixtures in the house, notwithstanding the fact that the unit price of gas has been reduced?" It is difficult to frame an intelligent answer to this question. Gas companies, without exception, seem to have evaded the question. The following would seem to me to be a fair answer. If a consumer's gas bill is larger than formerly the gas meter must have passed more gas than formerly. Assuming that there are no leaks, the following are some reasons which may explain the matter. The candlepower of gas has been reduced recently. Unless the consumer has substituted incandescent mantle burners for his flat-flame burners he must necessarily use more burners on the same fixtures to get the former degree of illumi- nation. This means increased gas consumption. Another explanation is that the consumer, tired of his poor light, may have been misled to buy new types of flat-flame burners, which often, though marked to burn only 3 or 4 cubic feet per hour, in reality pass per hour from 5 to 10 cubic feet of gas, particularly where the pressure is excessive, and unchecked by pressure regulation. A third reason is that in districts where the gas mains have become insufficient in capacity, the gas company carries more pressure of gas in the evening hours. Unless the consumer checks this by pressure-regulating devices, he will burn more gas, although perhaps not using a larger number of burners. Others have endeavored to explain the increased gas bills by calling attention to the fact that the specific gravity of the gas supplied at the present time has been reduced. The reduced specific gravity, combined with increased pressure, causes more gas to flow through the gas meter in a given time. This expla- nation appears reasonable enough, but I am not prepared to confirm it. Practical Hints for Gas Consumers 219 Various Household and Commercial Uses of Gas. 50. Consumers should bear in mind that at the present greatly reduced prices for gas there are numerous uses of gas in the household other than for light, combining convenience as well as economy. (a) Gas may be used in the kitchen for the various cooking processes. There is a large variety of excellent gas cooking stoves and ranges in the market from which one can select apparatus suitable to one's needs. Remember that the gas companies wjllingly assist the consumer in the selection of appli- ances adapted to their individual requirements. (6) Gas may be conveniently used in gas stoves, gas logs, and gas fireplace heaters for the occasional warming up of a room. (c) In the laundry the use of gas sad irons will be found ex- tremely convenient, and with proper care also quite economical. (d) When drying of clothes has to be done indoors, the install- ment of a clothes dryer heated by gas will be found advantageous. These clothes dryers are made in all sizes, adapted to the needs of large as well as small families. (e) Gaseous fuel is of the greatest convenience in heating water for the kitchen, for the bathroom, for shaving, etc., in one of the modern gas water-heaters, which are made in a variety of styles and capacities. (/) Finally, there are numerous commercial uses of gas, other than for lighting, which it is well to consider. Owners of small workshops will find it of advantage to look into the merits of the small gas engine for power use. "DON'TS" FOR GAS CONSUMERS. Don't think if your gas gives a poor light that the gas company is letting down, in the quality of gas. Your pipes or burners may be at fault. The gas furnished you is the same as that furnished to your neighbor, who has good light. Don't put in too small pipes when building your house. You cannot get a big stream, even of gas, through a small hole. Don't put in too small burners. It will be poor economy, for more jets will have to be lighted to get enough light. Don't expect your gas bill in December to be as small as in July; it is not possible, if you want to have light in dark hours. 220 Gas Piping and Gas Lighting Don't expect children and servants to be as economical of gas as you are; it isn't their nature. Don't leave your gas burning full when it ought to be turned out; you will be irritated by the sight of the next gas bill. Don't forget to keep your burners cleaned out. Don't use globes with too small opening at the bottom; the light will be cut off by them. Don't allow the gas to flutter and blow as it burns; it is simply wasting, making heat but no light. Don't leave your house alone and shut up a great length of time with- out notifying the company to remove the gas meter or shut off the gas. Some one else may get in and burn gas for you to pay for. Don't fail to go to the gas office when anything is wrong with your light, instead of complaining to your family or to your neighbor. (From the Columbus Gas Company's Book.) Don't look for a gas leak with a match or other open light. Don't fail to keep your burners clean. Gas companies furnish cleaners free of charge. Don't put on too small burners; it is poor economy. Don't use globes of too ornate pattern, or with too small openings at bottom ; they cut off light. The plainer the globes the better. Don't forget that gas as a fuel for cooking is cheaper than coal. Don't allow your gas-range burners to become foul. Don't fail to turn off your gas-range burners when not in actual use, or to turn them down to just the efficiency required when in use. It is very easy to waste gas. Don't fill your oven with gas and apply a match or light. Any self- respecting gas will explode under these conditions. Don't forget to read your meter occasionally. Don't expect your bill for lighting to be as small in winter as in summer. Don't blame the gas company if you receive a bill which seems unduly large. Remember that you control the gas consumption, the meter records it, and the company only reads the meter which you can do also. Don't be too sure that you did not use the gas as billed. Consumers are sometimes mistaken in this respect, and if you think your gas meter registers fast, the company provides a remedy. Don't fail to notify the gas company of any defects in the gas service. They will be promptly attended to. (From Cicero Gas Company's Book.) Practical Hints for Gas Consumers 221 Don't call an unbiased and fair-minded observer or counselor, who attempts to explain to you the mysteries of the gas meter, and who endeavors to show you why your meter is not at fault and points out to you the real cause for your high gas bills, a " champion of the gas meter." (THE AUTHOR.) A FEW POINTERS ON GAS. Have your gas meter placed in a convenient location, and where it will be least affected by outside changes of temperature, and keep your service pipe protected from frost. Use a little patient effort to learn the manner of measuring gas. Then you can read your meter every week, or oftener if desired, and have in your own hands a perfect check against fraud, or against waste on the part of your employees or servants. Carelessness or waste in using more burners a longer time or under a heavier pressure than necessary, is the main cause of high bills. The time has gone by when gas companies should desire the lighting bills of their consumers to be as large as possible. Their true interest lies in furnishing perfectly satisfactory light for the least possible money. Remember that the gas meter registers all that gas which is burnt unnecessarily or wastefully, or which escapes through leaks in the house pipes or at the fixtures. (Compiled from various sources.) CHAPTER XXII. SOME FACTS ABOUT THE GAS SUPPLY, (A.) The Quality and Price of Gas. From time to time the public and the newspaper press indulge in complaints about the " exorbitant " gas bills and the poor quality of the gas manufactured by gas companies. To an impartial observer both complaints appear generally to be without foundation in fact. While there is scarcely another private manufacturing industry in which the general public is so much interested as that of the supply and dis- tribution of gas, because it is a commodity in very general use, I venture to assert that nowhere else are so much ignorance and misconception of facts prevailing. This may be partly explained by the well-known truth that it is human nature to be suspicious and sceptical of anything which one does not understand . Of the making and selling of gas the public knows very little indeed, few people care to take the trouble to inquire at all into the subject, and many erroneous ideas and prejudices exist. Notwithstanding the fact that gas companies have in more recent years exerted much effort in trying to educate and en- lighten the gas consumers about the mysteries of gas making and gas burning, by freely given advice, by remedying unfavor- able conditions in cases where these, upon investigation, were found really to exist, by popular lectures on the use of gas, by exhibitions of gas appliances, for lighting, cooking, and heat- ing, etc., much still remains to be done in these directions to clear up popular fallacies and prejudices. Concerning the price at which gas is sold to consumers, it is doubtful if it ever occurs to the grumbling consumers to con- sider that the cost of manufacturing gas must necessarily depend upon three principal factors; namely, upon the cost of the raw materials (coal and oil), upon the freight rates from the coal regions to the gas works, including the cost of loading and unloading and trucking, and upon the cost of the labor engaged in the manufacture and distribution of gas. It is unavoidable, 222 Some Facts About the Gas Supply 223 therefore, that the cost of production of gas must change, and vary with the price paid for the two chief items entering into its manufacture, viz., coal and labor. The cost of coal at the mines is always subject to fluctuations, caused by strikes, and its transportation is greatly affected by the prevailing freight rates, which are generally high, owing to railroad combinations, and only fall when a contest between competing railroad lines takes place. The other item, the cost of labor, depends upon the rate of wages paid, and includes not only the wages of the laborers in gas works but such items as salaries, expenses of the distribution department, cost of meter reading, expenses for testing and repairing meters, for altering or repairing street gas-mains and street surfaces; for lighting, extinguishing, cleaning, or repairing street lamps, etc. It is fair to assume that gas consumers must be aware of the fact that the cost of coal has in recent years gone up; that a few years ago, for instance, the price of coal, owing to the prolonged coal strike, was extraordinarily high, in fact, almost prohibitive; that the freight rates have increased owing to railroad combines, and that the wages of laborers have also increased instead of diminishing. Notwithstanding these facts, gas companies in New York, for instance, are held, by an Act of Legislature, to a fixed price, namely of $0.80 per 1000 cubic feet of gas, irrespective of the future cost of coal, of oil, or of the rates of wages. It is well to remind consumers that when gas was first intro- duced (about 80 years ago) the price charged was ten dollars per 1000 cubic feet. This price was adhered to for many years, but it subsequently dropped to $7, $5, and $4 successively. Only twenty years ago the price was $2.50, which was gradually cut down to the 80-cent gas of to-day. From the fact that for a short period of time, during the war between the rival gas companies in New York, who have since consolidated, the gas was sold at 65 cents per 1000 cubic feet, a popular fallacy arose that the recent charge of $1.00 was an exorbitant one. This being the case, it seems proper to remind the public of the former charges as mentioned above. When a consumer discusses the price of gas, he is very apt to make comparisons with actual prices charged in other cities. Such general comparisons are, however, often extremely incor- 224 Gas Piping and Gas Lighting rect, and, to say the least, unfair. Cities situated in the coal or oil regions must necessarily enjoy the advantage of cheaper gas rates, as the item for transportation of the raw material is very much reduced in comparison with cities located remote from these regions. In no other branch of commerce or industry are comparisons made from the actual price per unit only, without taking the quality of the product sold into consideration. For example, a poor quality of paper, sold at one dollar a ream, may in reality be a great deal more expensive than a good quality of paper sold at the rate of two dollars a ream. The same applies to the cost of gas sold to consumers. Without a consideration of either the candle or illuminating power and the heating power, it is impossible, in comparing two kinds of gas, to say which of the two is the cheaper and which the more expensive. Is it not a fact that gas sold in London at 3 shillings, or about 75 cents, is dearer than gas sold at $1.00 in New York, when it is borne in mind that London gas is of 16 candlepower, whereas New York gas is from 22 to 26 candlepower? Take again the City of London as an example : Would it not surprise gas consumers to learn that in London the companies were some years ago obliged, and received parliamentary per- mission, to raise the price of gas, because of the growing scarcity of coal and the consequently higher price charged for same, and also because of the higher value of other materials and of labor. Yet, according to the London Journal of Gas Lighting, this is a fact, not only in London, but in many other English towns as well. In the State of New York, too, several instances have occurred, where, owing to the increased price for coal and higher freight rates, the price of gas was raised. The Mohawk Gas Company of Schenectady, for instance, announced recently an increase of 10 cents (from $1.20 to $1.30 net) per 1000 cubic feet, and as this company has, from time to time, voluntarily reduced its price, whenever the state of the coal market permitted, fair-minded consumers probably did not seriously object to the trifling advance. The cost of gas in London at the present time is nearly as high as in New York City, yet the item of laborers' wages alone is vastly higher here than there. Moreover, gas companies here are expected to do a great deal more for the public than in Eng- Some Facts About the Gas Supply 225 land or on the Continent of Europe. For instance, American gas companies always run the service from the street main to the building free of charge, and often are asked to do even some piping inside of the building, whereas in Europe it is the rule that the gas consumer must pay for every foot of service pipe laid for him. Again, here gas companies are expected to furnish the gas meter free, and to set and connect the same, whereas in London and other European cities the house owners must pay for this work and even for the meters. Compare again the gas service with the water service of cities. The house owner must defray all expenses connected with the introducing of water, for service, taps, shutoffs, and for the water meter where this is used. Not so for the gas service, which he expects to get, and does get, entirely free of charge, including the gas meter. Again the public should bear in mind how, in innumerable instances, gas companies are called upon, where there is trouble in the gas supply, and complaint made at the gas company's office, to look into the question of the house piping, fittings, and even the gas appliances, all of which is never expected from them in London or in Continental cities. (B.) The Candlepower of Gas. When gas burns poorly, it is usual for people to complain at once about the inferior quality, or the low and insufficient candlepower of the gas. Not many persons will stop to consider first, whether other causes might not exist to explain the poor illumination. It is desirable that the general public should know that the candlepower of the gas furnished to consumers is tested by officially appointed gas examiners regularly, not at the gas works, but at gas-testing stations located in different parts of the city. The published records of these gas tests offer sufficient proof that it is a rare occurrence to find the quality of the gas falling below the established standard. In Greater New York the charter requires that gas should be of at least 20 candlepower. In the month of September of the year 1900, the records of the gas-testing stations showed the illuminating power to have been from 22 to 26 candlepower, in other words always from 2 to 6 candlepower higher than required by statute, yet articles appeared in the daily press giving a list of the results of the monthly gas tests, with words like the following " gas somewhat improved in quality," thus 226 Gas Piping and Gas Lighting indirectly implying that the gas had before that time been below standard, whereas in reality it had always been kept more or less above the legal requirement. It is a fact, not well known to consumers of gas, that even a gas of high candlepower will not give a good illumination when it is burned under unfavorable conditions, such as poor, worn out, or corroded burners, insufficient size of the piping of the houses, or badly arranged gas pipes, or clogged services, or in cases where too many fixtures are being supplied from a small riser or service. Take the case, for instance, where gas burns well on the lower floors of a house, but gives dim flames on the upper floors : common sense should tell the occupants that it cannot be the candlepower of gas which is at fault, for the same gas is supplied to all parts of the house. There must, in such cases, be local causes affecting the lighting; for instance, the gas riser from the lower to the upper part of the house may be stopped up with rust. These matters are spoken of more in detail in other chapters of this book. I must, however, dwell further on the requirement of the candlepower of gas. It should be borne in mind that the expectations of consumers with regard to illumination have in recent years been increased, partly, no doubt, by the advent of electric lighting. On the other hand, it cannot be denied that the progress made in the last decade in the art of illumination by gas has been some- what in the nature of a complete revolution. This came about largely through the introduction of the incandescent gas lamp. An excellent illumination is now obtainable with gas of low candlepower by burning it with the incandescent or Welsbach mantles. But more than this, scientific men have discovered that a gas of low candlepower, burned with the incandescent mantle, gives actually far better results than does a high candle- power gas. No less an authority than Professor Dr. H. Bunte, of Carlsruhe, speaking of the conditions prevailing at this date in Germany, states that " incandescent gas lighting, as opposed to the older lighting by flat-flame andArgand burners, has assumed a pre- dominant position. . . . The fundamental factors, by which gas is valued, and the properties and manufacture of gas, have been entirely altered." Formerly illuminating power was regarded as the principal Some Facts About the Gas Supply 227 criterion of the value of gas, but this has now become of second- ary importance as compared with heating power. A large part of the gas used for lighting, and nearly all gas used for heat- ing and cooking is mixed with air in the Bunsen burners (giving the well-known bluish or greenish flame); this destroys the illuminating constituents of flames and only the calorific (or the heating) value of the gas is of any importance. Hence there should be substituted for the present illuminating candlepower standard a standard calorific value of the gas. The Boston Herald, under the heading of " A Standard of the Past," discusses this phase of the gas question in its issue of May 1, 1907, in the following words: " In discussing the various plans that have been put forward for governing the supply of gas furnished the consumers in this city, it should not be forgotten that in one respect at least we are behind the gas users of Europe. This is in regard to * 'candlepower." We still stick to a high candlepower for our gas, measuring it by the old-style fish-tail burner, a burner that in some European cities is as hard to find as would be a hen's teeth. For burning with mantles, for heating purposes and engines, high candlepower gas is not only wasteful, but for some reasons, at least, it is not so good as that with fewer illuminative units when measured by the old-fashioned standard. Throughout the United King- dom the tendency has been very marked both with the municipal-owned and private plants to lower the standard of candlepower demanded, and in Germany they have gone so far that candlepower is no longer mentioned, and gas is furnished capable of supplying a certain number of heat units. While the use of mantles has increased wonderfully in this city during recent years, we are still far behind our friends across the sea in this respect. In London, gas lighting in the streets is being steadily extended, even where there is keen competition with municipally-owned electric plants. Any basis of settlement, sliding scale or otherwise, for the Boston gas question should be with some provision for a reduction in the future of the number of lighting units supplied by a given amount of gas. By that change we would bring ourselves in line with progress in the business as it has been developed for use in stoves and engines. The fish-tail burner is as much out of date in comparison with the mantle burner as is a tallow candle in comparison with a kerosene lamp." In incandescent gas lighting the quantity of the illumination is dependent primarily upon the quality and nature of the mantle. At the present time every opportunity is offered to the gas consumer, who wishes a brilliant illumination, to get it, without an increase in the candlepower of gas and also without an 228 Gas Piping and Gas Lighting increase in the amount of gas consumed, by simply making use of the incandescent gas lamp in one of its many improved forms. Indeed, there is as a rule a reduction rather than an increase in the gas consumption, and, owing to their efficiency, the gas mantle burners are in some cases successful rivals to the electric lamp. It is to be regretted that nearly all cheap mantles at present sold are bad, and that the good mantles are rather expensive, but is not this equally true of many other commodities or articles sold to the public? Doubtless this state of things will be remedied in the near future by the manufacturers of incandes- cent gas mantles and burners. It will, furthermore, be of interest to gas consumers, who are inclined to complain about the insufficient candlepower of the gas, to learn that in London one of the three large companies obtained about eight years ago a concession from Parliament, reducing the illuminating power by two candlepower, so that now Londoners burn 14- candlepower gas (see the London Journal of Gas Lighting of October 9, 1900). The granting of this reduction in illuminat- ing power was largely due, no doubt, to the increasing use of incandescent gas burners, and of gas heating and gas cooking appliances. Close observations show that similar conditions prevail in the United States, and the time is probably not far distant when photometer or candlepower tests will be super- seded by calorific tests or tests of the heating value of the manufactured gas. CHAPTER XXIII. y ACCIDENTS WITH GAS. THE records of the coroners' offices in every large city show each year a list of fatalities due to the use of illuminating or fuel gas in buildings. The thirteenth annual re-port of the Board of Gas and Electric Light Commissioners of the Common- wealth of Massachusetts, published in January, 1898, enumerates 105 instances of gas escapes which happened during the year 1897, and which caused the death of 60 persons and injury to 74 others. A few of these cases were due to intended suicide, but the larger number were clearly accidents. In the city of New York, 388 deaths were traced by the coroner's office in 1903 to illuminating gas. Of these 130 were considered to be "suicide" cases, and 258 "accidental" cases. The casualties occurring in other states are undoubtedly equally large in pro- portion, and perhaps even exceed the above figures in the case of seaboard cities where a vast number of immigrants land every year, many of whom are not familiar with the management of As is well known, jnany gas companies now manufacture water gas which they enrich with naphtha. This gas contains a much larger percentage of carbonic oxide than coal gas, and since carbonic oxide forms the principal poisonous constituent of illuminating gas, a greater number of fatalities result in those cities where water gas is used. The percentage of carbonic oxide in gas varies from 6 per cent in coal gas to as much as 25 or even 30 per cent in water gas. Carbonic oxide is strictly odorless, and therefore pure water gas would be very dangerous to use. Fortunately, it cannot, per se, be used for lighting pur- poses, and must be mixed, or "enriched," with coal gas or naphtha to make it suitable for illumination. This admixture imparts to the gas the peculiar strong and pungent odor, by means of which it is readily detected, when it escapes un- burned in even small quantities. Notwithstanding this fact, the numerous accidents point to the necessity of diligent care in 230 Gas Piping and Gas Lighting the use of gas fixtures and fittings ; they also emphasize the need of popular instruction in the management of gas, and finally they tend to show that an official supervision of gas piping and gas-fitting in all classes of buildings would be as desirable as the official regulation of plumbing and drainage now enforced in a large number of cities. Illuminating gas (both coal and water gas) possesses another quality making it dangerous under certain conditions, i.e., when mixed in a certain proportion with atmospheric air (from 13 to 20 per cent) it becomes a highly explosive compound. Igno- rance of this fact is a prolific source of accidents and explosions. When gas escapes, it is imperative that one should not search for the leak with an open flame. Yet even the employees of gas companies frequently come to grief by a disregard of this simple rule. Witness the following account, taken from the columns of a daily paper: " Because of the repeated complaints of the odor of escaping gas being in evidence in the neighborhood of - Street, a gang of men was sent down there by the Gas Company to locate the supposed leak. After a hole had been dug near the curb in front of the heuse, the foreman went down, with a lighted lantern, to examine the pipes. The escaping gas was ignited by the flame, and an explosion followed, throwing the man out of the trench. The occupant of the ground floor was knocked down by the force of the explosion, and all the windows of his place shattered. The explosion also caused a fire." Similar severe accidents happen when an escape of gas occurs in the cellar of a building, or when a gas meter springs a leak. In all such cases the safe rule to follow is never to search for the leak with an open flame or lantern, nor to strike a match near the gas meter, nor even to handle any tool or instrument which may cause a flying spark. Many cases of gas asphyxiation arise from the ignorance of persons who have never used gas. Immigrants and travelers from remote country towns constitute a large percentage of these cases. Persons who have never lighted a gas flame before in their life, are apt, upon retiring at night, to blow out the flame in the same way as they would a candle or oil lamp, and the next morning they are found asphyxiated in their bed. Intoxicated persons sometimes commit the same fatal mistake. The Massachusetts Board of Gas and Electric Light Com- missioners considered several expedients to guard against this Accidents with Gas 231 accident. They suggested that a legislative act might be passed requiring in the sleeping rooms of cheap hotels and lodging houses the use of some kind of gas burner from which gas can- not escape except when lighted. At the gas exhibition held in New York some years ago, several inventions tending to accom- plish this object were shown, and some types of gas burners are now manufactured \vhich automatically shut off the sup- ply of gas when the burner is blown out, either by design or by accident, as, for instance, from a draft of air passing over a flame which has been turned down low. The danger in relying upon such safety burners arises from the fact that these appliances may not always prove to be reliable and durable, and may refuse to work at the proper moment. It is not denied that it is within the range of mechanical possibility to construct a device of this kind, which would be simple, safe, durable and at all times efficient. Encouragement should therefore be offered to inventors of this line of appliances. Another frequent source of accidents by asphyxiation is found in gas keys, which are worn out and have become so loose that they turn too easily. It frequently happens with such fittings that upon retiring for the night, persons turn out the gas, and accidentally or carelessly re-open the burner enough to cause a dangerous escape of gas. Many cases of fatalities recorded in official statistics are due to this cause. The remedy is too obvious to require any further description. Other accidents arise from fixtures which are defective by reason of the stop-pin being either absent (so-called " all-around keys" which persons unconsciously may turn too far), or because of its having fallen out. Such old-fashioned fixtures are, unfortunately, often to be found in hotels and lodging houses. Many years ago, the author suggested that the use of such dangerous fixtures should be pro- hibited by legislative act. The law should also provide for an efficient inspection of the gas fixtures in hotels, lodging houses, and similar buildings. The above-named commission proposed as a further safeguard a law prohibiting the use of gas in sleeping rooms containing less than a definite number of cubic feet. Fatal accidents occur through the stupid custom, still existing in some hotels, of turning off the gas at night from the bedrooms. Occupants often leave their gas flame turned down low, on retiring, and by reason of the practice mentioned, the flame becomes extinguished without the burner cock being turned off. 232 Gas Piping and Gas Lighting When the gas is again turned on early in the morning, it escapes through the partly open burner and asphyxiates the occupants before they awaken. This bad practice is not confined to hotels and lodging houses, but it also occurs in boarding schools, in apartment and dwelling houses. Equally bad is the practice of turning off the gas at the main service during the day, as it leads to similar dangers, by reason of people leaving gas cocks open when they attempt to light the gas early in the evening, before it has been turned on at the meter. Two cases in point were related in the daily papers not long ago, as follows: Case 1. " Yesterday the body of E. S. was found in his apartments. He had seemingly been asphyxiated with gas, which was issuing from a jet not turned off. S. went to bed sick at an early hour, leaving the burner turned down low. His brother-in-law always turned off the gas in the cellar so that no accidents would occur during the night. Early in the morning he used to turn it on again so as to make the gas avail- able in the gas stove which his wife used in preparing the morning meal. This practice resulted in the death of his boarder." Case 2. " T. C. was found in his rooms overcome by gas, and died later at the hospital to which he had been removed. He was in the habit of sleeping with his gas burning. That night the gas in che lodging house had been turned off for only a few minutes to make certain repairs. No one thought of the habit of the man sleeping with his gas burning. The turning out of the gas had, of course, extinguished the gas flame in the man's room, and when the gas was again turned on full force, it escaped into his room while he lay in bed sleeping and caused his death by inhala- tion." Gas explosions may also occur when attempts are made to thaw out a frozen gas meter with the heat of a flame. In this connection, the following extract from the report of the Inspector of Plumbing of Washington, D. C., of August 26, 1897, is interesting : " Some study was given, during the winter 1894-95, to determine the best practical method of obviating the dangers of accidental asphyxiation through the escape of illuminating gas, due to defects in old fixtures and pipes, and that investigation has been continued during the period cov- ered by this report. " The coroner expressed an opinion that the deaths which took place in January, 1895, at 922 G street S. W. and 33 H street N. E., were due entirely to defective gas fixtures. He at that time recommended that a thorough inspection of all buildings, especially sleeping apartments therein, be made relative to the condition of the gas fixtures. Two Accidents with Gas 233 similar instances were brought to public notice in December, 1896, and January, 1897, the two deaths being directly caused by accidental open- ing of seriously defective keys. " In February, 1897, a list of the principal hotels and boarding houses was prepared and sent to the commissioners with a request that it be determined if authority existed to make inspection of the gas appliances in these buildings. The opinion rendered by the attorney was an adverse one and no further action was taken. I consider that the con- ditions justify the enactment of a statute, allowing the entrance of my assistants for such examination, and compelling repairs after due service of notice. " That this subject is deemed of pressing importance in other muni- cipalities is evidenced by the report made to the Massachusetts legislature by the Board of Gas and Electric Light Commissioners of the city of Boston (February 10, 1897). This report states that four propositions have been considered, viz. : 1. "To require the use, in the sleeping rooms of hotels and lodging houses, of some kind of burner from which the gas cannot escape except when lighted. 2. " To prohibit the use of gas in sleeping rooms which contain less than a definite number of cubic feet. 3. " To provide for the systematic inspection of gas fixtures and piping by some duly authorized public official. 4. " To define by statute the amount of CO or other ingredient which may exist in the gas, and to prohibit the distribution of gas containing an excess of such ingredients. " The apparent conclusion reached by this board respecting the third proposition is that the number of fixtures (estimated at 1,200,000 burners in Boston) is prohibitive of the proposed inspection. * I do not agree with this conclusion, but consider it entirely feasible to make periodic inspection of the condition of a very large number of gas fixtures if the requisite authorization can be secured." A still more serious matter is the frequent escape of gas into houses from breaks or leaks in the street mains. These escapes may occur into houses which are not provided with a gas service. As long as the pungent odor of the gas warns the occupants of the leak, the danger of an accident may be averted. Unfor- tunately, the gas, after filtering through the soil, loses some- times its peculiar odor, and cases of entire families being asphyxiated from the escape of gas are by no means uncommon. Very often such escapes merely cause sickness or headache, and, 234 Gas Piping and Gas Lighting the true cause not being at once apparent, the gas company is not notified and the leaks are not immediately repaired. Such escapes are particularly dangerous in winter time, when, by reason of being heated, the houses act like huge chimneys in drawing up the gas-polluted air. Where the street surface is paved with impermeable pavements like asphalt, and in winter when other kinds of street surfaces are frozen hard, the escape into the interior of houses is much more likely to occur than where the pavement is an old-fashioned loosely jointed cobblestone pavement. The report referred to states that from 1889-1896, 13 cases of this kind occurred, in which 75 people were rendered unconscious. Finally, the air of houses may be continuously contaminated by slight escapes due to leaky house gas pipes, or to defective fixtures, loose bracket joints, or worn-out gas keys. The leaks may be so slight as to be hardly noticeable. In many cases of headaches, languor, nausea, drowsiness, prostration, or loss of consciousness, the cause is to be sought in a slight escape of gas. The public is generally inclined to attribute such illness to " sewer gas" entering the house through defective plumbing, and the true cause is seldom thought of. A writer in a recent issue of the New York Evening Post speaks about the danger as follows: " A frequent cause of neuralgia and headaches is the poison of illumi- nating gas. When the house is supplied with what is known as ' water gas ' a recurrence of such maladies should prompt a very careful investi- gation of the fixtures. Water gas contains a poison of admitted viru- lence, and the fact that it is colorless, tasteless, and odorless makes its power for evil the greater. Absolutely tight fixtures are the only pro- tection. . . . Periodical examination is essential, for what seems secure to-day may be insecure to-morrow. Old fixtures are likely to be loose i n screws or joints, the threads of the thumb screw may be worn out and turn at a touch to let the poison escape with no one the wiser, or in mov- ing furniture the arm of a chandelier or side bracket may be wrenched enough to permit its escape. A safe plan is to have each fixture put through what is called the pressure test. This properly done by a good plumber will show quickly any defects or chances for leakage." Not long ago, the writer had in his own house a case in point. When the gas was lit in the evening, a peculiar odor arose, which caused severe headache, but for which the reason could not be immediately ascertained, as the odor ceased completely in day- Accidents with Gas 235 time, when the gas fixtures were turned off. The house gas pipes were tested and found in a tight condition. The gas fixtures also showed no leaks. The gas company was sent for to clean out the main service, it having occurred to the writer that an accumulation of naphthaline in the meter or the house pipes or the service might cause the gas, when burning, to smell in the way it did. The service was thoroughly cleaned out; the meter was removed, emptied, and cleaned; the house pipes were blown out by means of a pressure pump, but all to no avail; the odor returned in the evening when the gas was burning. After much searching, the cause was at last found in slight leaks at the burner joints, which permitted an escape of unburnt gas only when the keys were open and the flames lit. These joints were then made tight with white lead and the odor immediately ceased. In the statistics of gas accidents, other less frequent causes appear, among which I mention the following : (a) Gas and electric fixtures so constructed that the gas key may be accidentally turned in the dark instead of the electric key. (6) Gas escaping from the gas cooking stove by reason of the water boiling over and extinguishing the gas flame. (c) The breeze from an open window blowing out a gas flame which has been turned down low, the gas then escaping unburnt and causing an accident. (d) A flame turned down low for the night being extinguished by a sudden reduction in the gas pressure. (e) The connecting rubber hose of a gas heating stove becoming either loose in the joint or completely detached and causing an escape of unburned gas. (/) Two gas keys, one for light, the other for a gas stove, being placed so near together that one might be mistaken for the other and turned on unintentionally. (g) The tubing of a gas chandelier or other fixture becoming split and permitting escapes of gas. (h) Disarranged electric gas-lighting fittings intended by the pulling of a chain to open a valve, letting out the gas, and at the same time to light it by a spark. (i) Finally, gas leaks may cause headaches or loss of conscious- ness, where gas escapes from the rubber hose connection to a table gas lamp. 236 Gas Piping and Gas Lighting The majority of cases quoted are clearly due to lack of a reasonable and ordinary care on the part of the gas consumers. What is much needed is the giving of plain instructions to gas users. Emphasis should be laid on the fact that illuminating gas is a highly dangerous substance, and that due care is required in its use. The danger of asphyxiation is somewhat greater where water gas is manufactured and distributed, for reasons explained heretofore. It is not the author's intention to create a prejudice by these notes against the use of lighting gas or gaseous fuel, for as long as it is confined in tight pipes, gas is perfectly harmless, and if burnt properly, or used with reasonable care, there is not the slightest danger connected with its use. Even the fire risk is comparatively small. Statistics gathered by German fire insurance companies show that in the five years from 1881-1885 14.7 per cent of the fires caused by lighting were due to gas, whereas 85.3 per cent were due to the use of kerosene and oil lamps. In 1892, 1089 fires arose from kerosene and oil, and only 80 fires from gas. CHAPTER XXIV. * DANGERS TO THE PUBLIC HEALTH FROM ILLUMINATING AND FUEL GAS. THE American Public Health Association, some years ago, appointed a committee of which the author was a member, to investigate the subject of illuminating gas in relation to health, and at the annual meeting of the association, held at Minneapolis, in 1899, the author submitted a paper bearing the title of this chapter, which paper is reprinted herewith in revised form. Owing to recent progress in the art of manufacturing gas, the subject is now much more difficult to treat than it was twenty or thirty years ago, when scarcely anything else but the ordinary lighting gas, manufactured by a process of distillation from coal, was known. About thirty years ago gas companies began the manufacture and introduction of the so-called water gas, and several investigations were conducted and reports made at that time * with regard to the dangers involved in the new gas. Still more recently, not more than sixteen years ago, the manu- facture of acetylene gas from calcium carbide began. While the use of acetylene gas is, at present, largely confined to iso- lated buildings not in reach of city gas works (see Chapter XIX) it promises a rapid development within the next decade. To discuss intelligently a subject of such great importance, and to make the work of a committee investigating the subject * See Dr. Samuel W. Abbott. " The relation of illuminating gas to pub- lic health," Sixth Annual Report Massachusetts State Board of Health, Lunacy and Charity, 1885. See Professors Sedgwick and Nichols, " A study of the relative poison- ous effects of coal and water gas," same report, 1885. Prof. Edw. S. Wood, " Illuminating gas in its relation to health." Vol. III. (Trans. A.P.H.A., 1877.) Dr. Jos. H. Raymond, " Illuminating gas; its history and its dangers." Tenth Annual Report, State Board of Health of New Jersey. William Paul Gerhard, " Accidents with gas." Amer. Arch., Aug. 6, 1896. Report of the Commissioner of Health of Brooklyn on Illuminating Gas. 1883. 237 238 Gas Piping and Gas Lighting effective, an intimate knowledge and practical experience in the manufacture and distribution of gas, in the work of piping houses for gas and in the different uses of gas, are necessary. It would, therefore, seem best to place on such a committee a chemist or chemical technologist, acquainted with modern methods of generation, purification, and analysis of gas; a gas engineer or a sanitary engineer, who has made a specialty of the entire subject of domestic and street gas-piping and gas light- ing; and finally a physician, health officer, or sanitarian, who should be well acquainted with the sanitary features and require- ments of lighting, with the unhealthful effects due to the com- bustive processes, and with the dangers due to gas escaping unburned. The aeriform mixture, commonly known as gas, is nowadays used not only as an illuminant, but also as fuel (for heating, cooking, and industrial purposes) ; in a few cities a special quality of gas, not fit for illumination, is distributed to consumers for use as gaseous fuel ; in other cities what is known as natural or rock gas is introduced into houses for like purposes (see Chapter VIII). Hence the scope of the inquiry would, perhaps, be enlarged by either omitting the word " illuminating" before the word "gas," or else using the term " illuminating and fuel" gas. For other reasons it seems advisable to omit the words " leakage from" and to call the subject " Dangers to the Public Health from Illuminating and Fuel Gas. " By way of introduction, the different known kinds of gas, their manufacture and composition, will be briefly reviewed; likewise the usual impurities found in them, and in particular their dan- gerous or poisonous ingredients. From a sanitary point of view, it is important to consider not only the danger incident to gas escaping un burnt, but also the effects upon health due to the burning of gas. Gas escapes and leaks may occur at the place of manufacture or the gas works, in the distributing system in the public streets, and finally at the places of consumption, in the houses, offices, or shops. The last subject is of particular importance, and hence will be more fully discussed under the headings of dangers due to the gas service pipes in houses, to the gas fixtures, and to the use and management of gas. Following this, it is desirable to review the remedies and precautions suggested or enacted for the lessening of the dangers and fatalities due to gas. Dangers to the Public Health 239 Different Kinds of Gas ' Their Manufacture and Composition. At the present time, we may distinguish the following kinds of gas, viz. : 1. Natural gas. 2. Coal gas. 3. Water gas. 4. Carburetted or luminous water gas. 5. Air or naphtha gas. 6. Acetylene gas. 7. Gas from oil, wood, resin, etc. Natural or rock gas consists of an accumulation of hydro- carbons found in nature below the surface of the earth. It sometimes flows freely at the surface, like the eternal gas fires at Baku, Russia, or else it is liberated by boring. It is really the same as marsh gas or light carburetted hydrogen, known in mines as fire damp. In burning it usually produces little light, the flame being bluish yellow, and is therefore suitable princi- pally as fuel gas, though some natural gas contains illuminating or heavy hydrocarbons, and can be used for lighting. Mixed with ten times its volume of air, this gas ignites with a violent explosion, when a light is applied. The composition of natural gas varies, as seen from the following three analyses : I. II. III. Marsh gas Hvdrosren 49.58 35 92 75.16 14 45 60 to 89 4 79 to 22 5 Ethylhydride .... Ethylene .... 12.30 60 4.80 60 4 to 18 56 to 2 94 Oxygen 0.40 1.20 Carbonic oxide .... Carbonic acid .... Nitrogen 0.40 0.30 0.30 2.89 traces to 0.26 0.28 to 0.66 Coal gas is made from bituminous coal, by a process of dis- tillation in closed retorts. It may be termed the ordinary illuminating gas, as it was the first lighting gas manufactured and distributed on a large scale. Such coal gas is really a more or less purified mixture of a number of distinct gaseous com- bustible substances, of which some are luminous, while others burn with a non-luminous flame. Its manufacture embraces three principal processes, viz., the distillation, the condensation, and the purification of the gas. When coal gas is distilled in 240 Gas Piping and Gas Lighting retorts, the resulting vapors which contain hurtful impurities are first condensed, and tar and water is thereby removed; the subsequent processes of condensation in condensers remove carbonic acid and some ammonia; in the washers and scrubbers ammonia is removed, while the purifiers free the gas of carbonic acid, sulphuretted hydrogen, and other gaseous sulphur com- pounds, by means of lime and oxide of iron. The composition of purified coal gas is about as follows: I. II. III. Hydrogen 50.2 (Pettenkofer) 49 40 to 50 Marsh gas Carbonic oxide Heavy hydrocarbon 29.8 7.9 4.3 36 7 8 35 to 45 4.5to 7.5 Nitrogen 7.8 100.0 100.0 Olefiant gas, small amounts carbonic acid. A few actual analyses of coal gas are here quoted, the differences in them being due to the kind of coal used in the manufacture of the gas. Boston Coal Gas. (Nichols.) London Coal Gas. (Lethe by.) Marsh gas .... Hydrogen .... . 40.0 .34.8 37.41 46.38 3.72 5.53 6.19 0.25 0.52 Light carburetted hydrogen . 39.5 Hydrogen 46.0 Condensible hydrocarbons . . 3.8 Carbonic oxide 7.5 Aqueous vapor 2.0 Nitrogen . 14.2 Carbonic oxide . . Illuminants . . . Oxygen . 7.0 . 3.4 . 0.5 . 0.1 Oxygen 0.1 Carbonic acid . . Nitrogen 0.5 Carbonic acid 6 Water gas or hydrogen gas is made by passing steam over incandescent carbon or glowing coals. The resulting gas is odorless and non-luminous, but owing to its large amount of hydrogen it burns with great heat, hence this gas is excellent for fuel purposes. The coal used in the process is anthracite coal. Theoretically, water gas is composed of 50 per cent hydro- gen and 50 per cent carbonic oxide. It should be pointed out that pure water gas contains a very large proportion of carbonic oxide, which is the dangerous element in all gas. Carburetted or luminous water gas is a mixture of pure water gas and petroleum, naphtha or cannel gas, the latter gases being heavy hydrocarbons mixed with it to give it luminosity, to Dangers to the Public Health 241 render it fit for lighting purposes and to give it a distinct odor. This is done by the so-called carburetting process. Since about thirty years a great many gas works (nearly two-thirds in United States, according to Professor Bunte) manufacture and supply this composite gas, the chief reasons for preferring this process being the reduction in first cost of the works, the easier purification, the smaller area required for manufacturing, the possibility of using coke, the doing away with some of the side products or residues, and the cheapening in the cost of manu- facturing the gas. There are many different processes in use for making car- buretted water gas (Lowe, Strong, Gwynne-Harie, Harkness, Tessie de Motay), and the composition of the manufactured gas, as well as its lighting qualities, vary greatly. A few analyses are quoted as examples: Composition of Water Gas. (Remsen.) Water Gas ( of Municipal G; 'N. Y.) (Wurtz. is Lfght Co. ) I- II. III. Hydrogen Marsh gas 30.3 21.45 38.05 11 85 36.34 20 55 Carbonic oxide 28.25 29 40 27 46 Carbonic acid gas . 0.3 0.10 35 Ox vsren 0.10 26 N^itro r en 6.85 3.71 2.56 Olefine 9 29 Paraffines 7.50 Illuminating hydrocarbons . . 12.82 12.48 Air or machine-made gas, or carburetted air gas, is a simple mixture of atmospheric air with the vapor of naphtha, benzol, petroleum, or gasoline. The use of such gas is largely confined to the lighting of isolated buildings not in reach of gas works. The apparatus for its manufacture consists, in its simplest form, of a blower and a generator. The latter is placed in a brick vault, at a good distance from a building, and is filled with refined gasoline, which is a very volatile inflammable liquid. A blower or air pump is placed in the cellar of the building; this is operated either by a suspended weight (which must be wound up same as the weights of a clock) or by a wheel driven by water. It forces air into the generator, which here takes up the vapors of the naphtha and so enriched is delivered to the house to be consumed (see Chapter XIX). 24:2 Gas Piping and Gas Lighting It burns with a tolerably good, luminous flame; the gas being very heavy flows comparatively slowly, hence large pipes and burners are required. The flame is seldom free from smoking. The gasoline itself, from which the gas is made, is a very volatile and highly inflammable liquid, which gives off vapors at ordinary temperature. Mixed with a certain proportion of air, the machine or air gas is very explosive. Acetylene gas is the latest comer in the field of gas manufacture. This gas has been known chemically since 1836 (Edmund Davy, chemist) as the most brilliant of illuminating gases. In 1861, the chemist Woehler, and in 1862, Berthelot, prepared the gas in the laboratory from calcium carbide and water. In the latter part of the year 1892, the French chemist, Henri Moissan, made small quantities of calcium carbide in a laboratory furnace. But the commercial manufacture of crystalline carbide on a larger scale in electric furnaces was discovered accidentally in May, 1892, by an electrician, Thomas L. Willson, of Canada. Before that time, calcium carbide was a very expensive chem- ical, costing about $2000 per ton; after Willson's discovery its price immediately dropped to $70. Acetylene gas has a very peculiar, easily detected garlic-like and unpleasant odor; it is an ignitible gas, rich in hydrocarbons, and is generated by bringing calcium carbide in contact with water. It is composed of 92.3 parts by weight of carbon, and 7.7 parts of hydrogen. When mixed with air, in a proportion from 1 to 4 up to 1 to 20, acetylene gas is very explosive, its explosive force being much stronger than that of coal or water gas. The more the gas is condensed, the more explosive it becomes, and in its liquefied form it is so dangerous that its use is at present everywhere prohibited. The purity of acetylene gas depends upon the purity of the raw material from which it is made. Calcium carbide always contains phosphorus, sulphur, and nitrogen, and unless purified the resulting acetylene gas will contain phosphoretted hydro- gen, sulphuretted hydrogen, and ammonia. The improved pro- cesses of manufacture of calcium carbide do away with these impurities. Purified acetylene is not as dangerous to breathe as coal or water gas; it takes also, in burning, less oxygen from the atmosphere, and creates much less carbonic acid in combustion than the ordinary gas. It is, too, of a much higher luminosity Dangers to the Public Health 243 than ordinary gas, burns with a white flame, and owing to its richness in hydrocarbons, special burners, with small orifices or jets, and burning only 0.5 cubic foot of gas per hour, must be used ; these give about 25 candlepower light against 16 candle- power of the ordinary 3- to 6-cubic-foot-per-hour burners. The ammonia contained in acetylene gas will form a chemical explosive combination with copper, hence copper gas-fixtures, piping, or generators should not be used. Numerous forms of apparatus for making acetylene gas have been devised. Practically, they all belong to one of the follow- ing three types of generators : (a) Those in which a measured quantity of water is supplied gradually to a large volume of calcium carbide, contained in a closed vessel. (6) Generators in which the carbide is immersed in water and then withdrawn, the action being repeated from time to time. (c) Generators arranged so that a measured quantity of car- bide is dropped into a large volume of water. The generator and the gasometer may be fitted up separately or together. From the point of view of safety, it is advisable to place the generator in a brick vault outside of a building (the same as with air-gas machines). Owing to the necessary use of very small burners, it will take a much longer time before a room, in which a gas cock is left open, will hold a mixture dangerous to health. The odor of acetylene being very peculiar and distinct, a small leak is rendered very noticeable. Quite recently a new lighting gas made from pure acetylene gas by dilution has been used, as the following item from the London Daily Mail shows: "The first place in the United Kingdom to be illuminated with the bright white light of ' Electroid Gas ' is Hunmanby, a Yorkshire village near Scarborough. This new illuminant is composed of acetylene with the admixture of inert matter and a proportion of oxygen. Its manu- facture is claimed to be of the simplest nature. The gas can be delivered through any ordinary gas main at the ordinary pressure, measured by means of gas meters, and charged for in the same way as is the custom where ordinary coal gas is used. The light is described as perfectly white, and equal to 250 candlepower, as against the average 17 candle- power of coal gas. " 244 Gas Piping and Gas Lighting According to an article by Dr. Paul Wolff in a recent issue of Glaser's Annalen fur Gewerbe und Bauwesen, the town of Schonsee, in West Prussia, is now supplied with acetylene gas from a large plant, designed for 2000 burners (Eng. Record, October 21, 1899). Finally, gas is made from oils, melted fat, resin, petroleum, peat, and from wood. Owing to the cost of these materials, only few oil or wood gas-works are in existence. Gas is made from petroleum or from naphtha by decomposing the same in heated retorts. Such gas requires no purification, is very rich in heavy hydrocarbons, but is too expensive to be sold in a commercial way. It is used more as a means to enrich the non-luminous water gas, and to render the same less dangerous in use by imparting to it a distinct smell. Impurities in Gas. Tests for Impurities. The gaseous impurities of ordinary coal gas are sulphuretted hydrogen, vapor of carbon disulphide, carbonic acid and ammonia. These reduce the lighting qualities of the gas, and the sulphuretted hydrogen, in burning, produces sulphurous and sulphuric acids, which are destructive to metallic articles, plants, and generally injurious. Sulphuretted hydrogen can be traced by holding a strip of paper, dipped in sugar of lead, which, in the presence of this impurity, becomes discolored and turns brown, the intensity of the latter color being an indication of the degree of impurity. Carbonic acid can be detected by leading the gas through lime water, which thereby becomes cloudy or white. The presence of ammonia is indicated by dipping a glass rod in muriatic acid and holding it over an open gas burner, when a white fog will form. The purification processes remove all but a small quantity of these gaseous impurities. y Dangerous or Poisonous Ingredients in Gas. While sulphuretted hydrogen is a poisonous ingredient, the quantity contained in well-purified gas is so small that it may be disregarded. From a health point of view, the really dangerous poisonous ingredient of both coal and water gas is the carbon monoxide. This is present in both kinds of gas, the amount in coal gas being from 7 to 10 per cent, and in carburetted water Dangers to the Public Health 245 gas from 25 to 40 per ceiit. Chemistry teaches that carbon monoxide, or carbonic oxide, is a colorless and tasteless gas, a little lighter than air, which burns with a bluish flame, forming carbonic acid. It acts as a strong poison, producing asphyxia and often death when inhaled in "small quantities. Its toxic effect is due to a combination with the haemoglobin of the blood, which is thereby rendered unfit to take up oxygen in the lungs. In coal gas as well as in carburetted water gas the carbonic oxide is simply a diluent, the same as the marsh gas. It does not appear to be practically possible to remove it from ordinary coal gas, though it is stated that a part of it can be removed from water gas. As regards the danger from explosions, the light carburetted hydrogen, and to some extent the defiant gas or the heavy carburetted hydrogen, are the dangerous elements, for these mixed in certain proportions with atmospheric air, form a mix- ture which explodes when ignited. Dangers in the Use of Gas. When lighting gas was first made, objections were raised against its use, because of the products of illumination, when the gas was burnt. But nowadays it is a well-established fact that no serious danger to health, beyond the mere contamination of the air, results from the burning of purified illuminating gas. The contamination of the atmosphere can, of course, be counter- acted by proper and sufficient ventilation. Theoretically the products of burning gas are water and carbonic dioxide. Unburned gas, however, is dangerous, no matter how made. Escapes of unburned gas are therefore to be avoided. The dangers are twofold, viz., first, asphyxiation, and second, explosions; the latter sometimes accompanied by fire. The danger of asphyxia is greatest with pure water gas; next comes carburetted water gas; then gas made from wood, coal gas, and finally natural gas. Neither the air gas nor the acetylene con- tain carbonic oxide, though the breathing of such gas may be injurious for other reasons. The danger of gas explosions, caused by mixtures of gas and common air becoming ignited, is present with all kinds of gas, though the proportions between gas and air, which are explosive, differ somewhat with the different kinds of gas. 246 Gas Piping and Gas Lighting Escapes or Leaks of Gas. Dangerous escapes of gas may occur either at the works, where the gas is manufactured, or in the distribution system in the streets, or finally in the houses when the gas is consumed as fuel or as illuminant, or for power purposes. Gas escapes in buildings are either due to leaks, or to carelessness or ignorance in the use of gas, or to accidents.* Dangers Incident to the Manufacture of Gas. At the gas works, where either coal or water gas, or carburetted water gas is manufactured, the workmen are to some extent exposed to the danger of explosions due to escaping gas, and on the other hand they are liable to suffer from breathing gas which may escape from the retorts, the gas-holder, or other points in the works. It is stated on good authority that acci- dents at gas works from the inhalation of coal or water gas are comparatively rare. Where water gas is manufactured, there is of course a greater danger than with coal gas, owing to its larger percentage of carbonic oxide. Good ventilation in the gas works is always an essential condition. The workmen in gas works are also liable to suffer from exposure to the heat and from sudden changes of temperature. The ammonia of unpurified gas attacks the mucous membrane of the respiratory organs. Besides this, the workmen may suffer from the vapors caused by the extinguishing of the burning cokes, and, in the purifying department, workmen who clean and empty the lime boxes are liable to inflammation of the eyes from the gases and odors. Dangers Incident to the Distribution of Gas. The gas distribution system embraces the street mains, the house and lamp services, and the gas meters. Gas leaks caused by a break of a street main are generally noticeable by the intense smell of gas, and in the case of smaller gas works by the sudden falling of the station gas-holder. There is always some leakage of gas connected with the dis- tribution mains, the gas escaping either at the joints or from imperfect pipes, or finally from breaks in the mains. From 7 to 10 per cent of the daily output is estimated to be lost by leakage * See Gerhard, W. P. Accidents with gas American Architect, August 6, 1898. Dangers to the Public Health 247 from the gas mains. In 1894 the gas leakage per mile of main in Philadelphia amounted to the enormous volume of 871,000 cubic feet per annum. Cases of asphyxiation occur when workmen make connections with the gas mains (so-called " tap- ping"), or when they go into trenches, in which a broken gas main is to be repaired. The chief danger connected with escapes of gas under the street surface is that the gas will often find its way through the soil and escape into the houses located along the street. When such gas leakages occur, the characteristic pungent odor of the gas is sometimes partly or completely lost by filtration through the soil. Where this is the case, it is much more difficult to detect a leak or break, and the buildings and their occupants along the line of such defective or broken gas main become exposed to tw r o grave dangers, namely, the danger of explosion and of asphyxiation. Many cases are on record of people having become asphyxiated in houses not provided with any gas ser- vice. This danger, as was first pointed out years ago by Pro- fessor von Pettenkofer, is particularly great in winter time, and this for two reasons: first, the street surfaces are apt to be frozen hard and will not permit the gas to escape upwards where it would do no harm and where it might be quickly noticed; then again it is well known that houses in winter time act like chimneys by reason of the temperature inside being higher than that outside. They, therefore, draw in the ground air, as it were, and with it the gas which has leaked into the soil. The dangers are, of course, aggravated by the fact that at night, and in winter particularly so, the doors and windows of bedrooms are usually kept closed. * Professor von Pettenkofer relates a great number of instances where not only one person, but some- times entire families, have been found in the morning asphyxiated by gas which entered houses in this manner. Sometimes the gas escaping from the main will follow along the line of house sewers and will thus gain entrance to the cellars; in other in- stances it follows the tubes or conduits which enclose the elec- tric light wires. Professor Wolffhugel has drawn attention to the fact that coal gas may also lose its peculiar odor in passing through floor deafenings and plastered ceilings. Where no asphyxiation occurs, dangerous explosions may happen by reason of the escaping gas mixing with the air. The striking of a match, or the bringing down into the cellar of an 248 Gas Piping and Gas Lighting open flame will speedily cause this result. Only recently, a fatal gas explosion occurred in a residence street in New York City, in a house which had not been occupied for the entire summer, but where a workman had entered in the morning to make some improvements. Five minutes after he was seen to enter the house, an extremely violent explosion occurred >. which blew out the entire front and rear walls of the three-story brick and stone building, causing a fire in this and several adjoining houses, and resulting in the death of the unfortunate workman. The cause in this instance was a broken gas main, from which the gas had been escaping into the cellars of the houses along the street for probably many days or weeks. The danger of being asphyxiated is in all such cases much greater where the gas manufactured is the so-called carburetted water gas. Where otherwise healthy persons, living in houses not supplied with gas, awake in the morning with persistent headaches or nausea, it is always well to bear in mind the possi- bility of carbonic oxide poisoning from gas escaping in the manner described above. In case of a break of a street gas main, the most important thing to do, until the gas company can shut off the gas and reach the leak, is to keep open all windows of the cellar and basement, also to avoid having any open light. It is difficult to suggest a remedy for the conditions named, except that wherever an escape of gas is noticed in a street it should be immediately reported to the gas company and it should act promptly in the matter, and, if necessary, cut off the gas from the entire street rather than continue to expose the nouses to such dangers. A German chemist, Professor Bunte, has suggested a ready method for testing the tightness of gas street-mains. Small holes from 12 to 16 inches deep are bored, at intervals of 6 to 10 feet along their line, and in each opening an iron tube 0.5 inch in diameter is placed, which has within it a glass tube containing a roll of test paper. This paper is dipped into a solution of palladium chloride, and any trace of gas escap- ing from the main at once acts upon the paper, coloring it a slight brown or even black, according to the extent of the leak. If, on the other hand, after, say, ten minutes, the paper remains white, it is a safe indication that at the point tested there is no escape of gas.* * Another method is suggested in Hartenfels' patent gas-leak indicator. Dangers to the Public Health 249 To the distribution system belong also the house and lamp services and the gas meter. The house service should be laid with the same care as is required for the inside gas-piping system. The tapping with the main should be done carefully with a good ratchet brace and hard steel drills. In certain soils, it is advis- able to protect iron sendee pipes against corrosion by painting them. A leak which shows itself in the cellar at the point where the service enters should be at once repaired by notifying the com- pany to whom the piping belongs. Breaks in services to street lamps are sometimes indicated by the fact that a street lamp suddenly burns very dimly. The consumers' gas meters, which form the connecting link between the house service and the house pipes for gas, should also be tight and all connections made with the greatest care. Connections with iron pipes and fittings are preferable to those of lead. Accidents sometimes occur to workmen of the gas company when replacing a defective gas meter or cleaning out house sendees that have become stopped up. In all such cases, the greatest care should be observed to avoid asphyxiation. Dangers Incident to the Gas Piping in Houses. In piping houses for gas it is always well to bear in mind the dangerous nature of the gas to be carried in the pipes. Of whatever kind the gas may be with which the house is to be lighted, whether natural gas, coal gas, air gas or acetylene gas, the piping should be absolutely tight in the joints and the tight- ness should always be ascertained by carefully testing the gas- piping system after completion. (For a description of how to test the gas piping, see Chapter XI.) It has been pointed out by scientific investigators, that even slight gas leaks in houses, when going on for a long time, will have an ill effect upon the health of the inmates. They will suffer not only from head- aches, vertigo, and nausea, but also in some cases from sore throats.* Quite often such gas leaks and their effects are erro- neously attributed to "sewer gas." Larger leaks of gas are dangerous, first, by reason of persons becoming asphyxiated, and second, because the gas when mixed with air and brought in contact with a flame -will cause explosions or a fire. Many *See Gerhard's "Gas Lighting and Gas Fitting." 250 Gas Piping and Gas Lighting accidents are annually recorded where persons have searched for a gas leak with an open flame, and even mechanics, who should know better, at times risk their lives by this bad practice. In laying out the gas-piping system for a building, it is there- fore obviously of the utmost importance to so arrange the pipes, in size and manner of distribution, as to avoid at any point in the system the possibility of a sudden reduction in the gas pressure, for, where this happens, a flame which has been turned down low is liable to go out, and when the pressure is re-estab- lished death, by asphyxiation, may result through the escape of the gas. Although this matter was not unknown, it has been pointed out, for the first time, I believe, by Mr. Faxon, an arch- itect, of Boston. The matter will be referred to again under the heading of " Management of Gas." (See also Chapter V.) A few points of caution may be useful: First, in piping a house, always keep the gas pipes away from bell wires, for cases are on record when such bell wires in constant contact with the gas pipes have gradually cut the pipe, causing a hidden leak of gas which was often extremely difficult to find. Second, gas pipes should always be kept away from steam and hot-water pipes, and also from hot-air flues, smoke pipes, and from electric service wires. Where small leaks of gas in the pipes of a house are suspected, a very simple method for detecting these is to watch the small index hand of the gas meter.. Wherever this moves, when no gas is burning and no gas is used in the house, there must be some- where a gas escape. Sometimes a gas leak may be noticed by a rumbling sound in the gas meter when all the burners are closed. Dangers Incident to the Gas Fixtures. In the gas fixtures, where gas is either burned for illumination or else for cooking or heating purposes, there are a number of points which require serious attention. First, there is the joint where the fixture is attached to the gas piping or to the gas outlet. Except for the few temporary connections by means of rubber tubing, this joint is nearly always a fixed joint. It, therefore, should be made with the same care as any other joint in the pipe system, but the makers of gas fixtures, who usually attach the latter, are very often guilty of carelessness or bad workmanship. Next come the fixtures themselves. Of whatever material Dangers to the Public Health 251 they are made, the tubing through which gas is conveyed to the point where it is burnt, should be absolutely tight. It would be well if all the gas fixtures were tested before leaving the factory, for owing to the fact that the gas keys are seldom absolutely tight, it is a difficult matter to test the gas fixtures in a house after they are once connected. The gas keys, which govern the flow of gas, are very often found to be loose in the joint or else worn out, and in that case a constant, though small, escape of gas may result. Keys which turn too hard are equally bad, as accidents may happen by reason of the gas not being entirely shut off. Numerous fixtures have either folding or extension or telescopic joints. All such joints constitute places where an escape of gas may occur. Particular attention should be called to the danger of old-fash- ioned gas fixtures with so-called "all around" cocks, that is, having keys without stop pins. The writer has held long ago that the use of such fixtures should be prohibited by legislative act. Where the keys are provided with pins, these are often made of too light material and break or snap off. The joints of extension fixtures should be watched with particular care. So- called water-joint pendants are liable to have the water evaporate, and it is best to substitute glycerine for the water. Very often the tubing of chandeliers corrodes or splits and gas leaks result. Where portable table lamps are used, the rubber tubing may become worn out or cracked, and permit the gas to escape. All gas keys should be properly greased and loose keys should be tightened to avoid the slightest smell of gas. The joint where the gas burner is attached to the fixture should also be made tight, as it otherwise may leak gas when the latter is turned on. Accidents may occur from all the causes named. In the Massachusetts statistics of deaths from asphyxiation, a few other causes are pointed out, of which the following may be mentioned: Combination gas and electric fixtures in which the gas key may be turned on, being mistaken for the electric lamp key. The use of the so-called independent cocks is also somewhat dangerous when the two keys are placed together, one of them controlling the lamp and the other a connection to a gas stove, as the one may be turned open by accident when the other is closed.* * See "Accidents with Gas," by William Paul Gerhard, Amer. Arch., Aug. 6, 1898. 252 Gas Piping and Gas Lighting Heating and cooking fixtures should also be connected with care and should not have any leaky places. Where rubber tubing is used for temporary connections, accidents may occur from the tubing slipping off the joint or becoming sufficiently loose to permit an escape of gas. Where gas pressure regulators are used at the meter to control the gas pressure, they should be carefully examined for tightness, for very often slight leaks are found in such appliances. Each single leak may be ever so small, yet the aggregate of leaks in a house may lead to a serious contamination of the air and to bad effects on the health of the occupants, due to slow poisoning. Dangers Incident to the Use and Management of Gas. Numerous accidents occur annually in the use of gas for lighting, cooking, or heating, through either carelessness or ignorance. The largest number of accidents, probably, occurs from ignorant persons blowing out the gas, or from turning it off and subsequently turning the cock on sufficiently for the gas to escape unnoticed. This is particularly liable to happen in hotels and lodging houses, where persons from remote country districts, or emigrants, who have never used gas before, take rooms; but it also happens now and then in private families, in the bed- rooms of servants, not acquainted with the use of gas. Fatal accidents usually occur in small rooms having no ventilation, while the occupants are asleep. Other accidents are the result of the bad practice of turning a gas flame down low, particularly in bedrooms. This is always ill-advised, for such a turned-down flame may be either blown out by a draft of air from an open window, or else it may be extinguished by a sudden variation or reduction in the pressure. When this happens in a small bedroom without ventilation there is great danger of persons becoming asphyxiated, par- ticularly so if water gas is used. Much can be done to avert this danger by a proper arrangement of the gas piping in houses. Another dangerous custom is to shut off the gas at the main service, or at the gas meter during the night, and numerous accidents, some of them fatal, have resulted from it. It is almost equally bad to turn off the gas at the meter during the day. Dangers to the Public Health 253 Notwithstanding the universal introduction of gas lighting, there are still many persons who would be benefited by receiving plain instructions on the use of gas in the household. Gas companies would benefit themselves and the public by paying more attention to this matter. Among the statistics already quoted may be found numerous deaths or accidents due to a faulty management of gas. Among the more remote causes the writer finds the following mentioned : In one of two adjoining rooms supplied with gas from one so- called prepayment gas meter, a man retired for the night when the gas supply from the meter was exhausted, but forgot to close his gas burner. The occupant of the adjoining room came home late at night, dropped a coin in the slot of the gas meter and got a fresh supply of gas, which meanwhile also escaped in the adjoining room, killing the occupant. The danger incident to the use of automatic or quarter-in-the- slot gas meters is also illustrated by the following recent occurrence in New York City, which caused the death of two victims : " An automatic gas meter ran out in an apartment after the majority of the household had gone to bed. In the early morn- ing hours some one of the household, after rising, put a quarter in the meter and the gas began to flow through the gas jet in a bedroom, the occupant of which had left the burner open when the gas went out the night previous. Gas filled the room, and the occupant was found unconscious, and after being removed to the hospital, died after several hours. A lady, occupying an adjoining bedroom, was also overcome by the gas, and likewise died from the effects of gas poisoning." Escapes of gas and explosions have also happened in the use of gas cooking stoves, where the boiling water, running over the vessel, extinguished the flame. It has already been mentioned that the so-called independent gas connections, with two keys, may lead to accidents by the wrong one being turned by mistake. Where the gas in the cellar freezes in winter time, it is dangerous to attempt to thaw out the gas meter or the gas service with a flame. A gas meter should never be examined with a burning light, nor should any tools be used near a gas meter which is known to be leaky, on account of the danger of flying sparks. 254 Gas Piping and Gas Lighting Remedies Suggested. According to the official statistics of the Board of Gas and Electric Light Commissioners of the State of Massachusetts, 105 gas accidents occurred in the year 1887, causing 60 deaths and 74 injuries. In the year 1898, 101 accidents occurred, causing 77 deaths and 45 injuries. While some deaths were due to suicidal intent, the majority of cases were accidents which might have been prevented by a stricter inspection of the gas piping and fixtures. It cannot be overlooked that the danger is a serious one, and one that is sure to increase as the use of carburetted water gas becomes more universal. Leaks of coal gas produce un- pleasant symptoms and sometimes cause loss of consciousness, but an exposure to the more dangerous water gas would, under similar circumstances, result in the death of the victim. With- out a desire to draw comparisons as to the relative dangers from sewer air and from illuminating gas poisoning, the writer has always held the view that both are equally preventable by proper supervision of buildings, old and new. In recent years, the supervision of gas piping pnd gas-fittings has been agitated in numerous places, among others in Boston, New York, Philadelphia, and in Washington. In the first-named city this agitation has resulted in the enactment of laws govern- ing gas piping and the inspection of such work in all new build- ings. A similar law was introduced years ago in Albany, but for reasons difficult to explain the bill was killed. At present, however, the gas piping of all new buildings in New York City is inspected and tested before use by the municipal building department. Among the safeguards to be applied, I mention the following: First. The enactment of official regulations regarding the arrangement of the gas pipes in buildings and the provision for official municipal inspection and for testing all work in connec- tion with it. It is advisable that all manufacturers of gas fixtures should test their output at the factories. Second. The periodical inspection of gas-lighting fixtures and other gas appliances in hotels, lodging houses, and tenements by the municipal authorities. Precautions against gas asphyx- iations are particularly necessary in the case of cheap hotels and lodging houses, frequented by people unacquainted with the use of gas. Dangers to the Public Health 255 Third. The prohibiting of the use of gas in all sleeping rooms without proper provision for ventilation, and in bedrooms of less than a stated number of cubic feet capacity. The danger of exposure to escaping gas becomes aggravated by sleeping in very small bedrooms. Fourth. The use of so-called automatic burners in the sleep- ing rooms of hotels and lodging houses. The term "automatic" in this connection is intended to designate a gas burner from which gas cannot escape without becoming immediately ignited. Several ingenious so-called " self-lighting " burners have been patented within a year or two and are now placed on sale. If a person should blow the gas out where these burners are used the gas will become automatically lighted and no asphyxiation can result. Fifth. It has also been repeatedly suggested to restrict by law the amount of carbonic oxide in gas and to prohibit the dis- tribution of any gas containing more than a stated quantity of this poisonous ingredient. In the writer's judgment, it will be a difficult matter to enforce such a statute, and managers of gas companies may surely be expected to oppose any such measures, as in recent years they found it to their advantage, on account of lessened cost of production, to manufacture a carburetted water gas instead of the coal gas. Under all circumstances, diligent care should be exercised in the use of gas fixtures and gas fittings. This, together with an official supervision of the gas piping, and with popular instruc- tions disseminated by gas companies to their customers, would accomplish much good in preventing fatal accidents in the future. CHAPTER XXV. ^ DANGERS OF GAS LEAKAGE (continued). IN the preceding two chapters the author has given his own views and observations on the dangers from gas leakage. The subject has become one of vast importance, and may be viewed from two different points, namely: 1. From the standpoint of the sanitarian, who looks upon it chiefly as a serious danger to health and life. 2. From the point of view of the underwriter, who sees in the frequent gas escapes and leaks dangers to property and risks of fire. The following quotations, drawn from the various sources indicated, are given in order to emphasize the absolute necessity of taking efficient steps to eradicate the evil, or at least to reduce it to a minimum. I should, perhaps, point out that with the exception of the first report quoted all others appeared after my own paper on the subject was prepared. From a pamphlet published in September, 1897, by the City Club, of New York, I quote the following sentences : " The enormous leakage loss of gas from mains is not only a public nuisance ; it is in a high degree dangerous to life and property. . . . Explo- sions in sewers, subways, and in manholes, of gas which has leaked from the gas mains are of frequent occurrence, entailing much public incon- venience and great expense for repairs. . . . Notwithstanding the repairs constantly in progress, the leakage of gas from street mains and defective service connections is enormous. . . . Experiments should be undertaken to determine whether some reasonable means of abating this nuisance, with all its attendant evils, is not available. The danger from these leaks is materially enhanced by the increase in the area of asphalt pave- ments. " The occurrence of a number of fires and explosions, studied in the light of these facts, may be assumed to be due to the gas leakage, and warrants the belief that this important subject should be further investigated. " The Committee on Lighting and Heating of the National Board of Fire Underwriters, issued a Report dated December 256 Dangers of Gas Leakage 257 28, 1899, on "The Fire Risk of Gas Main Leakage under Imper- vious Street Mains/' from which the following is quoted: " From the insurance standpoint, gas leakage from mains in asphalted or other impervious street pavements is important, as it increases the fire risk of buildings fronting on such streets. " The leakage from gas mains, service connections, and service pipes is much greater than is generally known. It is asserted on good authority that the normal leakage of 6-inch gas mains averages 225,000 cubic feet per mile per annum; that of 12-inch gas mains averages 450,000 cubic feet. " From reports received from fifteen American gas companies, large and small, the leakage appears to be vastly greater, in some instances nearly three times as much as the above figures indicate. " In Massachusetts the leakage is somewhat smaller, viz., 202,475 cubic feet for an average diameter of 6 inches. " This is a matter of grave concern to the fire underwriters. Leakage which formerly escaped gradually upwards, now follows the paths of least resistance, when street surfaces are practically air-tight ; it follows spaces around gas services, escaping into coal cellars and vaults, while some reaches either the sewers or the subways." In the Scientific American of 1904, I find the following: " Whereas water leakage is chiefly a question of municipal extrava- gance, gas-main leakage is a much more serious matter, especially when it occurs under asphalt or other practically gas-tight pavements. Of the gas thus lost, some is held in the superficial earth strata and creates the familiar nuisance in connection with street excavations. Some leaks into subways and sewers, and is occasionally heard from in explosions which hurl manhole covers high into the air and rip up sections of streets. (Such explosions are usually recorded by the reporters as ' sewer gas ' explosions.) " Most of the gas leakage, however, follows along the mains and works its way into cellars and coal vaults following the soft and pervious filling around gas and water services. This constitutes a very serious menace to life and property. " The case of the Hotel Windsor Fire in New York a few years ago is now assumed to have been due to an escape of gas, and the cause of many mysterious and costly fires may be looked for in the same direction. " Can we afford to put down impervious pavements until we learn how to minimize gas-main leakage? " Gas leaks are caused largely by expansion and contraction of the pipes. The total movement due to the range of summer and winter temperatures 258 Gas Piping and Gas Lighting exerts such power that the strongest materials cannot resist it, those irresistible forces therefore cannot be disregarded. " Wrought-iron pipes with steam-tight screw joints have been tried in place of cast-iron pipe with caulked joints. But even with wrought- iron pipes the threads are stripped, the joints are pulled apart, and rigid connections are broken. " Gas mains are also subject to the jar of the surface traffic, and to unequal settlement ; excavations near them increase the leakage. " In underground mains, rigidity is fatal to tightness and durability, and elasticity as well as flexibility should be secured. " The first cost of mains per unit of length is of vastly less consequence than freedom from leakage and repairs." An editorial in The Metal Worker of 1904, on " Tightness in Gas Mains," contains the following sentence: " It is said that possibly as much as 50 per cent of the gas generated at the works is lost before the consumer is reached. The consumer must necessarily pay a price sufficiently high to cover the loss. . . . The public utility corporation supplying gas should be forced to exercise the utmost care in laying its system of mains. . . . Possibly, when the gas company is made to feel that there is talk of restricting the retail price of gas, it will take measures to reduce to a minimum the losses which now seem to be regarded as unavoidable. From the standpoint of economizing . . . and from the standpoint of sanitation, in preventing the dissemination of a poisonous gas, the question of tightness in gas mains is one of no little importance. " In Insurance Engineering, a well-informed monthly magazine of New York City, occurs the following : " Who can tell how many fires, in New York and other cities, whose ori- gins are reported as ' unknown/ are really due to gas leakage? From one to two hundred recorded gas fires occur in New York City alone each year. It is an alarming question of the first magnitude. " Gas-saturated buildings and streets constitute a menace of the most dangerous description. . . . The perils against which people require insurance are largely of their own making, or exist on account of their ignorance or tolerance. . . . The gas-leakage peril, with its retinue of variegated calamities, can be regulated and reduced, if not eliminated wholly." The Philadelphia Medical Journal, of March 4, 1899, brought the following article, headed "The Increasing Dangers of Illu- minating Gas." " The occurrence, only a few days apart, of three instances of asphyxia- tion in this city by the accidental escape of illuminating gas should direct Dangers of Gas Leakage 259 public attention to the dangerous character of the illuminant. In the instances alluded to no less than sixteen persons were overcome and five deaths resulted. In this number are not included cases of attempted or successful suicide, by this agent, of which also several have been reported. " A point of danger, concerning which knowledge is not general, is the fact that, since the lease of the Philadelphia Gas Works, by the United Gas Improvement Company, an increasing quantity of water gas is being mixed with the coal gas, which many suppose constitutes the sole illumi- nating agent dispensed. Water gas is distinctly a more lethal agent than the ordinary illuminating gas, possesses no noticeable pungent odor, is particularly penetrative, and not only acts much more rapidly in pro- ducing asphyxiation, but produces effects far more difficult to overcome than does coal gas. Even when resuscitation and apparent recovery is made, the action of water gas upon the blood is such that an impaired state of health, temporary or permanent, according to the degree of asphyxiation, must inevitably result. " For the protection of the public, this important matter of the con- stant supply of so dangerous an agent should be hedged about with more safeguards than at present exist. Among the more obvious protective measures that should be recommended is the requiring of all companies manufacturing and selling illuminating gas, to give public notice of the use of any kind of water gas, such statement, with a caution as to the danger of the illuminant, forming part of every bill for service sent out by the company. In addition, municipal legislation should regulate the proportion of carbon dioxide f in the gas supplied, at least in the resident sections during what may be called the ' sleeping hours/ limiting such proportion to about 12 per cent. The character of the gas burners and fittings and their testing would also seem appropriate matters for regu- lation by the city government. Observance of such laws could be enforced by appropriate penalties. The concomitant possibility of civil suits for damages, in the event of death or injury, resulting from violation by the gas companies of any of the provisions having public safety in view, would also, doubtless, have effect in producing some degree of caution in the observance of legal points of liability. "The gas companies seem to have three malevolent aims: 1. To ruin our eyes by gas which does not illumine. 2. To ruin our bank accounts by compelling us to burn great quantities of gas, in the hope of lighting our rooms. 3. To ruin our health by vitiation of our atmos- phere. If we are rebellious, they propose actual death by asphyxiation. "Note. In the above editorial a slip of the pen made us say, ' carbon dioxide ' instead of ' carbon monoxide/ The latter is the gas present in water gas; it is the more dangerous of the two forms because it has the greater combining power with oxygen ; hence the statement in the t See explanation in the NOTE. 260 Gas Piping and Gas Lighting Press, by a gas official, apparently in reply to the editorial, that in the illuminating gas of this city far less than 12 per cent of carbon dioxide is used while there is a larger percentage of carbon monoxide, is most appli- cable to the contention by this Journal that cautions concerning the dangerous character of the illuminant should form part of the gas com- pany's service. The statement in the same interview, that the two gases are ' almost equally fatal/ is fallacious. Carbon monoxide is not only more surely fatal, but its after-effects, particularly upon the oxygenating power of the red corpuscles, are far more lasting, a condition of per- manently impaired health usually resulting when resuscitation from the immediate severe effects of the gas is had. Since the last writing two more deaths from this cause have been reported. Is it not time some step should be taken? " Commenting on this article, the New York Tribune wrote: " For the protection of the public against the dangers of illuminating gas, the Philadelphia Medical Journal, in a vigorous editorial, urges the absolute necessity of more safeguards than at present exist. Among the more obvious measures, with this end in view, it recommends requiring all companies manufacturing and selling such gas invariably to give public notice of the use of any kind of water gas, such statement, with an explicit caution as to the danger of the illuminant, .forming part of every bill for service sent out by the company. In addition to this, the Journal emphasizes the necessity of municipal regulation, of the pro- portion of carbon monoxide in the gas supplied, at least in the resident districts, during what may be called the ' sleeping hours/ limiting such proportion to about 12 per cent. Nor should the character of the gas burners and fittings be neglected in such supervision. That such regulations are of immediate importance is evident." Again, we find the subject mentioned in The American Archi- tect ol July 26, 1902: " An interesting discussion on gas leakage and its possible effect upon health was held at a- recent meeting of the New York County Medical Society. Annually in the large cities the gas companies expect to have a leakage of over one thousand millions of cubic feet of gas. In recent years this has become much more dangerous in its possible effects than in the early days of gas lighting when ordinary coal gas was employed. The gas produced in closed retorts by the destructive distillation of coal contained only a very small amount of the most poisonous ingredients, the carbon monoxide, or blue gas. Since water gas has come to be em- ployed almost exclusively for illuminating purposes the percentage of carbon monoxide present in illuminating gas is over 30 per cent. There has been a suggestion in recent years that pure water gas should be employed in cities for heating purposes. In order to be useful for illumi- Dangers of Gas Leakage 261 nation, water gas must be carburetted that is, saturated with cer- tain naphtha derivatives. It is these substances which give the water gas, as made at present, its characteristic penetrating odor. They also some- what dilute the more poisonous gases which are present. The gas expert who discussed the subject at the meeting referred to said that ' if pure water gas was to be supplied for heating purposes, the only safe place to live in New York City would be outside of it/ Present conditions in our large cities add to the dangers of gas leakage. Our pavements, especially in quiet residence streets, are usually asphalt, and are thor- oughly impermeable. Gas that escapes from the mains is confined beneath the streets until it finds its way into the houses or into the sewers. There is no doubt that severe anaemias are becoming more frequent in city life. Dr. Lloyd pointed out at this same meeting that some of these anaemic conditions, associated with febrile temperature, malaise, and headache, are traceable almost directly to sewer gas. As it is well known that ordinary sewer gas does not affect the health of workmen who are many hours each day engaged in the sewers, it would seem that only when large amounts of carbon monoxide find their way into the sewers, and thence into the houses, for the gas is highly diffusible, that so-called sewer gas takes on such pathogenetic influence." (From American Medicine.) Finally, I quote from Tfie Metal Worker these sentences : " The leakage of gas in dwelling houses and other buildings is a source not only of annoyance, but frequently of disaster. The experience of Pittsburg with leaky natural-gas pipes and burners has been especially unfortunate and has led to the utmost precautions being taken to pre- vent the escape of gas from its proper channels. In the case of natural gas, however, the danger is very much greater than with the ordinary illuminating or coal gas, which possesses a decided odor that permits of its presence being readily discovered. The first intimation that natural gas gives of its escape is quite likely. to be an explosion. " Notwithstanding the fact that coal gas has so marked a smell that the average nose will quickly detect it and if properly directed trace it to its point of escape, there appear to be many who seem to think they can see the gas more distinctly than they can smell it, and, therefore, whenever a gas leak occurs they go hunting for it with a light. It must be con- fessed that this method is apt to be successful so far as revealing the presence of gas is concerned, but, unfortunately for the investigator as as well as the house in which the gas is escaping, an explosion, sometimes little and sometimes great, usually precedes the finding of the leak. It is so natural to pick up a light when looking for anything, never mind what it may be, that the danger of doing so in the case of escaping gas when the point of leakage is the object of search is too frequently missed sight of until the explosion calls it to mind. The first thing to do when 262 Gas Piping and Gas Lighting a strong smell of gas is noticed in a house is to extinguish all the lights, and if possible intrust the search to some one who has had experience in the matter and knows what is best to be done. This advice, of course, should not be followed strictly when the gas is only smelt in one room, for then a little common sense applied to a search will often discover a gas burner turned on or something out of order that can be easily set to rights". A writer in a recent issue of the Boston Journal of Commerce gives some valuable suggestions on gas leaks, their repair and detection, from which we quote as follows: " A leak may be occasioned from a variety of causes, such as a fracture in the pipe from imperfect welding, from corrosion, bad fitting couplings, sprung joints in the gas meter caused by wrenching and twisting in attaching a regulating device by an amateur ' wrench fiend/ a leaky dome or gas-holder in a regulator attached to the meter, etc. When a leak is discovered, if in the pipe or couplings, it can be temporarily stopped, until a plumber's service can be obtained, by covering or filling the aperture with white or red lead, or with sealing wax or beeswax, and, as a last resort, a cloth can be saturated with molasses or any sticky sub- stance and wound about the leak. The locality of a leak may be deter- mined at times by taking a sponge and saturating it with a solution of strong soapsuds and applying it to pipe, couplings, etc., upon which it will form a thin film which the escaping gas will blow up into a soap- bubble. A leak may also be determined by passing the hand, if warm, over the pipe, as the gas, being of a cold nature, produces a sensation of chilliness when coming in contact with a warm hand. The writer then refers to the trouble occasioned by leaks between ceilings which are not readily located, and when found are not easily reached. The danger of investigating with a flame is illustrated by a case that actually hap- pened where a man looking for a leak mounted on a step-ladder, and against the advice of others, proceeded to light a match in the hope of setting fire to the gas where it escaped from the pipe, and thus locating the source of the trouble. The result, as expected, was an explosion, and the writer closes with the wise remark: ' Like many another fool, he did not believe it was loaded until the mischief was done/ Mixed within an iron cylinder and exploded with a flame, illuminating gas and air are the source of power in a gas engine, and if when used in such small quantities they have to be confined in an iron chamber to prevent damage, it is little wonder that a room, full, not to say a house full, of the mix- ture when exploded, should do considerable harm." CHAPTER XXVI. HISTORICAL NOTES ON THE DEVELOPMENT AND PROGRESS OF THE GAS INDUSTRY. IN the following I shall not attempt to give a complete history of the gas-lighting industry. Those who are interested will find ample material of this character in the bibliography on gas lighting following this chapter. I shall confine myself to a sketch of the development of gas lighting in Greater New York, with brief notes interposed relating to other cities. In the early days of the Dutch settlements of New Amster- dam and Breuckelen, as New York and Brooklyn were then called, the "burghers" or citizens, who went about the streets after dark, carried their own lanterns with them. Later in the history of both cities, the lighting of the streets was made a duty of the citizens. In 1697, the first street-lighting ordinance was passed in New York, which ordained by decree of the Corporation that "every 7 householders should unite to pay the expense of burning a candle in a lantern, suspended on a pole from the window of every seventh house on nights when there was no moon. " In New York City, public street lampposts of wood were first erected and maintained, at the expense of the city, in the year 1762; these posts carried lamps which burned oil, and oil lamps were continued in use up to the year 1823, when gas lighting was first introduced. "The street oil lamps of New York were tended by a regular force of lamp lighters who went about every morning with a can of oil, scissors, and a supply of wicks, and carried a small ladder, mounted on which they blew out and trimmed the lamps for the next night's service. At dusk the same perambulation occurred when the lamps were lit by means of torches. " (John T. Doyle, " A Boyhood in old New York.") Contrasting the present manner of lighting street gas lamps with the former primitive methods, the late Mr. Charles H. Haswell, C.E., in his " Reminiscences of an Octogenarian," states that " the lighting of the oil lamps involved the use of a ladder, a 264 Gas Piping and Gas Lighting vessel of spirits of turpentine, a lantern, and a torch, and if by the severity of the weather .the torch was extinguished, the relighting of it, before friction or "locofoco" matches were known, was a dilatory matter. In Brooklyn, now a borough, and once a sister city of New York, it is related, that owing to the increase of vice and crime on the streets at night, householders were recommended, in 1800, " to put candles in their front windows on dark nights as a convenience to those having to be upon the streets, and that was the genesis of street-lighting in Brooklyn/' as related in the Brooklyn Eagle " History of the City." In 1820, the streets of Brooklyn were for the first time lit up by means of street posts carrying oil lamps. The lighting of the interiors of houses, stores, theaters, and churches was accomplished, prior to the* ad vent of gas lighting, by means of both oil lamps and candles, the candles being made of spermaceti or tallow. " It was so different and attended with so many difficulties and inconveniences, compared with the facilities we now avail ourselves of, that it is worthy of record. The instruments of illumination were oil lamps and spermaceti or tallow candles. The lamps required attention to trimming of their wicks and to guard them from smoking, and the candles required repeated " snuffing" and would occasionally run or drip, as it was termed, frequently involving damage thereby, as in ballrooms, dancing parties in dwellings, etc., as such places were illuminated by chandeliers with a great number of candles thereon, some one or more of which would drip, and fortunate were the parties who did not receive drops of spermaceti upon their dresses." (Chas. H. Haswell, " Reminiscenses of an Octogenarian.") About the facilities of procuring a light at that period in the history of the two cities, when phosphor matches were as yet unknown, the same author relates the following: " The question has frequently been put, how we put up with such inconvenient methods? The only reliable artificial method was that of the construction of a tinder box, filled with tinder of well-scorched rags, a flint and a suitable piece of steel; or by the rapid opera- tion of a steel wheel rotated by drawing a long cord previously wound around its axis; to the face of this was applied a flint, the sparks elicited by it falling upon the tinder, to which, when ignited, a sulphur or bituminous match, as it was termed, was Development and Progress 265 applied and lighted. French phosphoric matches carried in a case with a vial of a phosphoric mixture and matches were altogether unreliable." Owing to the difficulties involved in these inconvenient methods, it became customary to keep tapers floating in oil lighted in bedrooms, sickrooms, in the city fire- engine houses, and other places where light might be quickly wanted at night time. Later on (about 1830), a brimstone match was introduced and soon became universally used. Gas lighting was introduced in England in the beginning of the nineteenth century. A London theater is said to have been lighted by gas in 1803; in 1807 Pall Mall was lighted by gas lamps, and street lamps, placed on the Westminster Bridge, were lit by gas in 1813. In 1823, twenty-three cities in England had gas illumination. Paris adopted gas lighting in 1816, Vienna in 1818, Berlin in 1826, Dresden in 1828. In 1850, twenty-six German cities had introduced gas lighting. Some early experiments with gas were made in New York in City Hall Park in 1812, and continued the next years, while Baltimore had some gas light in 1807, and Philadelphia in 1807. New York City was the third city in the United States to intro- duce gas lighting more generally, Baltimore having adopted gas in 1816 and Boston in 1820. The first steps to make use of the new method of illumination were taken in New York in 1823 and in Brooklyn in 1825. The city of Cincinnati adopted gas lighting in 1841 and New Orleans in 1835. In other countries, the use of gas did not begin until after the first half of the last century. Thus in Japan, Yokohama, in 1868, was the first city to use gas lighting. In 1823 the New York Gas Light Company was incorporated with a capital' of $100,000 and its first president was Mr. Samuel Leggett. The company was given the exclusive privilege, for thirty years, of laying gas pipes in the streets in that part of the city lying south of Grand Street. In September, 1823, some gas mains were laid in the principal streets, and in the same month the president of the gas company gave a reception in commemoration of the event, and his house at No. 7 Cherry Street, is said to have been the first New York residence in which illuminating gas was introduced. In 1825 266 Gas Piping and Gas Lighting gas mains were laid in Broadway from the Battery to Canal Street, consisting like the water mains of wooden bored logs, tapered at the ends. The first gas made by this company was distilled from resin, which was at that time obtained in large quantities from the South. Coal, although known before this, time, was not much in use for domestic purposes, and the heating of dwellings, stores, and factories was usually accomplished by means of wooden logs; wood was also the fuel used in the kitchen stove. Coal was at that time being imported from Liverpool and Newcastle, and was accordingly very expensive. The American anthracite coal was used in the districts where it was mined, and though some of the coal was shipped to the Eastern States by way of the canals, it was only after the advent of the railroads that coal was transported in large quantities and became cheaper in price. Between the years 1825 and 1830, illuminating gas came more and more into general use. In 1827 the former wooden lamp- posts were replaced by cast-iron lamps, and street gas-lamps were first lit in the month of June, 1827. In as late a period in the history of New York as 1858 or 1859, the street gas-lamps, which were then rather far apart, were not required to be lighted on moonlight nights, and as a result, when the calendar indicated moonlight, there was often no light in the streets although the sky was cloudy, overcast, and dark. When the complaints from citizens about this became too loud, it was changed to the present practice. It may also be of historical interest to mention that gas fixtures, gasoliers, and even the gas burners were formerly imported from England. On October 23, 1826, the New York Theater, afterward known as the Bowery Theater, was opened and was the first theater building in New York City lighted by gas. The price charged at that time for 1,000 cubic feet of gas was ten dollars, which has gradually dropped to the present price of eighty cents per 1,000 cubic feet, this price being fixed by Act of Legislature. In 1830 the second gas company, viz., the Manhattan Gas Light Company, was incorporated with a capital of $500,000, and was given the privilege of supplying the territory of the city lying north of Grand Street. Thus Grand Street formed the boundary line between the two gas companies then doing business in the city. The Manhattan Gas Company began the manufac- Development and Progress 267 ture of gas from coal. The price of gas at this time dropped to $7.00 per 1000 cubic feet. While street illumination with gas lamps was regarded as a great improvement, the introduction of the use of gas in houses was rather slow in the first years. It is stated that, not unlike the experiences in London, many householders and landlords of New York protested at first against the introduction of gas lighting into dwellings, for fear of explosions, and continued to use oil lamps and wax candles by preference. The New York and the Manhattan Gas Light Companies were the two original companies in Manhattan Island. Since their incorporation, a large number of other companies have been started, some of which have again become absorbed by the consolidation of several companies, so that their original name has disappeared. The third company in New York was the Metropolitan Gas Company, organized in 1853, which also began manufacturing coal gas. A keen competition was carried on for years between the Manhattan and the Metropolitan Gas Companies, until they finally mutually agreed to divide the territory, the Manhattan Company supplying the territory between Grand Street and 34th Street, and the Metropolitan Company that above 34th Street. The independent settlements of Manhattan ville and Yorkville (subsequently called Harlem) were about this time supplied by another gas company, the Harlem Gas Company. In 1848 the price of gas fell to S3. 50, and in 1855 it was fixed at $2.50, but the companies at that time charged in addition a rental for the gas meter. This meter rent was abolished in 1867. In 1870 still another company, the Mutual Gas Light Com- pany, was incorporated, and met at first considerable rivalry from the three oldest companies. This company was the first to make coal gas enriched with naphtha, and furnished gas of 20 candle-power. In 1876 a French gas engineer, Tessie de Motey, introduced in New York a process for making hydrogen gas, and the result- ing brilliant gas light, made under his process, was much admired and sought for. This system, however, required the laying of two separate mains, one for oxygen gas, the other for hydrogen gas, which were brought together at the burner and created a very white light not unlike the lime or calcium light. Capitalists 268 Gas Piping and Gas Lighting became interested in this process and organized the Municipal Gas Light Company, with works at 46th Street. Subsequently, this company made a kind of water gas enriched by naphtha, by a process suggested by Tessie de Motey, modified by Mr. Wilkinson and now known as the Wilkinson process. This gave a light of great illuminating power. Another gas company was started in 1876, viz., the Knicker- bocker Gas Company, with works at 99th Street. The price charged for gas in 1878 was $2.00. In the year 1880, New York City was supplied by nine gas companies, viz., the New York, Manhattan, Mutual, Municipal, Metropolitan, Knickerbocker, Harlem, Central, and Northern Companies. Soon after this date a consolidation of companies took place, and six companies, the New York, Manhattan, Metropolitan, Municipal, Knickerbocker, and Harlem, became thereafter known as the "Consolidated Gas Company." The price of gas was fixed at $2.25. The Mutual Gas Light Company was the only company on Manhattan Island which remained opposed to the Consolidated Company. There were in 1880, in New York City, about 860 miles of gas mains in the public streets, and 23,231 street lamps. In 1899 there were more than 1300 miles of gas mains and over 27,000 gas lamps. More than 531 miles of city streets and 70 acres of parks and public squares are lighted by gas, the annual cost per lamp to the city varying from $12 to $28. Stockholders from the old Municipal Company started, in 1882, the Equitable Gas Light Company, which built new works in 1884. Still later the Standard Gas Light Company was organ- ized with works in 115th Street, and made gas from oil. This was the first company to lay a large number of miles of wrought- iron gas mains with screw joints, the intention being to avoid the large amount of leakage of gas from cast-iron gas mains with lead-caulked joints. Still later, the East River Gas Company was organized with works located at Ravenswood, L. I., and it built a tunnel under the East River to supply New York. In 1898, the Equitable and the East River Gas Light Com- panies combined under the name of the New Amsterdam Gas Company. In 1900, there were four principal Gas Light Com- panies in the Borough of Manhattan, viz., the Consolidated, the Mutual, the Standard, and the New Amsterdam Companies. In many cases mains of different companies are located in the Development and Progress 269 same street, thus giving the consumer the choice between several gas companies. In 1899 there was a "rate war," and since 1900 all companies have combined so that at the present time there is practically no competition. The last step in the organization movement was the acquisition by the Consolidated Gas Company, in 1900, of all competing plants, and furthermore the merging of the gas and electric lighting interests of New York City under one ownership and management. The Brooklyn Gas Light Company was the first company to be incorporated, in 1823, in Brooklyn, the population number- ing then only 9000 inhabitants. Notwithstanding this early incorporation, gas was not introduced for street lighting until the year 1848 or 1849, but from this period on, gas lighting grew rapidly in favor, so that in 1852 there were 50 miles of gas mains laid and 1200 gas lamps put up in the streets. The second gas company to be incorporated was the Nassau Gas Light Company, which began to supply gas in May, 1873. A third company, the Fulton Municipal Gas Light Company, commenced operations in 1880 ? and besides supplying its own district, furnished also gas to the Metropolitan, the Citizens',' and the People's Gas Companies. Another company was the Williamsburg Gas Company, which supplied gas to the Eastern District. In 1893 there were eight gas companies in Brooklyn, with a total of about 600 miles of street mains. About the year 1896 all these companies consolidated under the name of the Brooklyn Union Gas Company. Besides the large companies mentioned, there are in Greater New York a number of smaller companies, supplying the out- lying or newly annexed districts. The quality and candle-power of the gas supplied by the gas companies is controlled and tested in the Boroughs of Manhattan and Brooklyn by officially appointed gas testers and examiners. The many complaints made from time to time by gas consumers about the poor quality of the gas supply are, as a rule, not due to any wilful reduction in the quality of the gas by the com- panies. Such complaints generally arise from insufficient size or defective arrangement of the gas piping in buildings, or else from the fact that in many streets the gas mains have become too small to supply the district. 270 Gas Piping and Gas Lighting Many years ago, when there was but a single gas company in a district, the running of gas pipes in houses was controlled by the companies, and the regulations for interior gas piping and for the distribution of gas, as issued by them, had to be strictly followed before the company would set a gas meter in a house. Each building, after being completely piped for gas, was rigidly inspected and the piping tested by an inspector from the gas company. This practice, owing to the sharp competition between the different companies, has in recent years been given up, and the quality of the gas piping work done in the common and cheaper classes of buildings has rapidly deteriorated. Many dwelling houses now exist which have gas pipes of insufficient size, and where gas log fires and gas stoves are supplied from small risers or branches intended originally for but a few light- ing burners. In many houses the gas burns dim when lamps are turned on simultaneously on different floors, and the flames begin to burn with more brilliancy whenever some are turned off. In all such cases the main service pipe, or the house pipes, or both are too small. In other instances, the fault is due to obstructions in the service pipe by tarry matter or naphthalene. For all these reasons, it became quite desirable that there should be a similar supervision and control of the work of gas fitters as was practiced by the Department of Buildings over the plumbing work in new houses. A few years ago laws were passed embodying this feature, and nowadays the Building Department exercises control, not only over the drainage and plumbing but also over the gas piping. A similar inspection of the gas piping exists in Boston. Until about the year 1878, gas lighting was the only means of lighting, from one central source or station, the streets and squares, and the interiors, of small as well as large buildings. At this time appeared the first electric arc lamp, giving a white light of great intensity, which, however, could be used only out- doors or at railroad stations, in large exhibition halls, factories, halls of audience, and in big commercial stores. The years 1881 and 1882 mark the advent of the Edison electric incandescent lamp. It was this which gave the first real impetus to the competition between gas and electricity. Development and Progress 271 The electric lamp was at first expected to interfere seriously with the business of the gas companies. Up to that date, gas burners had been used chiefly in the form of either flat-flame or Argand burners. The Siemens and other forms of regenerative gas burners, in which both the gas and the air are heated before combustion, were now put on the market as new forms giving more concentrated and stronger light. The electric lamp, however, was much more expensive in use than these gas lamps, and gradually gas companies began to feel safe again. It was later on found that the introduction of electric lighting had in reality a most beneficial effect upon the gas industry. Yet the electric incandescent lamp had some intrinsic advantages, such as greater safety from fire, less heat- ing of the surrrounding air, less vitiation of the air by products of combustion, and more convenient control of the lighting and turning off of the lamps. These palpable advantages caused further improvements of gas lights. About the year 1886 some improved and more eco- nomic regenerative lamps appeared, and soon afterwards came an invention, which was destined to revolutionize gas lighting: namely, a burner in which a non-luminous flame raised a specially prepared mantle to incandescence. This lamp became known as the Auer or Welsbach lamp from the name of its inventor. It used very much less gas for the same intensity of illumination, but was at first somewhat imperfect. It w^as much improved during the years 1887 to 1892 by the original inventor as well as by others. The improved lamp gave a light that was much more agreeable to the eyes, and gave three times the amount of light with only half the consumption of gas. The fact that in recent years the annual output from gas works has steadily increased is partly explained by the increasing use of gas as fuel, but it was also largely due to the improvements effected in gas burners. Dr. C. W. Siemens predicted this for the gas industry when in 1882 he said: "I venture to think that gas lighting will hold its own as the poor man's friend, and the time is not far distant when both rich and poor will largely resort to gas as the most convenient, the cleanest, and the cheapest of fuels. " From an interesting paper on " Incandescent Gas Lighting," by Professor Dr. H. Bunte, read some years ago before the International Gas Congress at Paris, I quote the following : 272 Gas Piping and Gas Lighting 11 Incandescent gas lighting, as opposed to the older lighting by flat- flame and Argand burners, has assumed during the past decade the predominant position in Germany. The Welsbach lamp is now the recognized form for both public and private use; the older types of flames are continually losing ground. It has thus effected a complete revolution, not merely in regard to the illuminating effect and the economy of gas lighting, but even the fundamental factors by which gas is valued, and the properties and manufacture of gas have been entirely altered. " Formerly ' illuminating power ' was regarded as the principal cri- terion of the value of gas. Now by far the greater part of the gas, whether it is used for lighting or for heating, is first of all mixed w^ith air in the Bunsen burner. By this means the illuminating constituents of flames are completely destroyed and the heating effect of the Bunsen flame alone comes into play. " The quantity of light yielded is, in incandescent lighting, no longer directly dependent on the quality of gas as made in the works and dis- tributed to the consumer. It is primarily dependent on the nature of the mantle which is brought to the luminous state in the Bunsen flame. It is, therefore, a matter of prime interest to the gas industry to follow the improvements in the manufacture of Welsbach burners, and the effi- ciency of the mantles on the market. " The incandescent gas lighting owes its illuminating power and bril- liancy entirely to the high temperature of the flame, therefore the grounds on which the properties of illuminating gas are estimated, and the methods used in its manufacture, must be modified, because since the introduc- tion of Welsbach burners the production of light has resolved itself simply into a question of heating. " Under the former regime of flat-flame and Argand burners the greatest value attached to the production of a gas, rich in the so-called heavy hydrocarbons (etylene and benzine) ; the lighting effect of the flame depended entirely on the presence of these constituents. But as incandescent lighting and the use of non-illuminating gas for heating and cooking continue to spread, these illuminants formerly so essen- tial become less and less valuable. " For the determination of the quality of gas a photometric test of the illuminating power with a bat's-wing or Argand burner can no longer form a proper criterion. It is the calorific value of the gas which now plays the most important part. " When the gas industry is freed from the antiquated control of tests of lighting value in flat-flame and Argand burners, it at once acquires a freedom in the selection, both of raw material and methods of manu- facture, which is of supreme significance in respect, not only of its whole future development, but also of the supply of towns with light, power and heat by means of gaseous fuel." Development and Progress 273 In the course of time, mantles of increased luminosity, which were at the same time less destructible and fragile, were manu- factured, and simultaneously the cost of good mantles was reduced somewhat. The latest development in gas lighting is the inverted incan- descent gas lamp, which gives a much better downward dis- tribution of light, with shorter and therefore less breakable mantles, and which also permits the designing of more artistic forms of gas fixtures. Simultaneously herewith, the upright or vertical incandescent gas lamps were much improved by the use of specially ground prismatic globes or shades, the so-called "holophane" globes, which enable the throwing of the light where most wanted, i.e., either outward, upward or downward as may be desired. Another improvement, introduced since 1898, was the use of an artificially increased gas pressure in the incandescent lamps. In a comparatively short period of time great and wonderful improvements have been made in the construction of gas burners, gas lamps, gas fixtures, and gas globes. These important im- provements, and similar ones in electric lighting devices, to which I cannot refer as it would be exceeding the subject matter of this book, have brought about a vast change in the appearance at night of our streets and squares, of our dweUings, stores, factories, theaters, and numerous other buildings. Thus we see that during the last two decades gas lighting and electric lighting have become close competitors. Great progress has been made in both forms of illumination and the advantages which always follow in the wake of a sound competi- tion are exemplified in this friendly battle between the two rival modern modes of lighting. This competition will doubtless be kept up, the development of the art of illumination will make further strides, and the public will be ultimately benefited, while the question: "gas or electricity? " will lose much of its former importance. The increasing use of gas as fuel for both heating and cooking leads naturally to a brief consideration of the kind of fuel used in the household in former times. At the beginning of the nine- teenth century, wood was the common fuel used in New York for heating and cooking. The wood was largely oak and hickory, 274 Gas Piping and Gas Lighting which were considered the best, though chestnut and gum- wood were also used. The wood came to the city on sloops or schooners, and the cargo was, on arrival of the vessel, purchased by cartmen in such quantities as they desired. They then drove through the streets selling their entire load or portions to customers. The carts were generally accompanied by men who sawed and split the wood, and put it into the bins in cellars. Very little coal came to New York in the days before the advent of the railroads, as has already been told. Only the rich could then afford the luxury of burning in their parlor grates bitumi- nous coal, shipped to the United States from Liverpool and New- castle. Many of the cooking operations were universally per- formed in open fireplaces, fitted up with large iron cranes, swung on hinges, which ran across the 'back of the chimney, and from which the cooking pots were suspended by iron chains or hooks. The roasting of meat was accomplished in what was called a "Dutch oven ' ' or else in a " roasting jack," or spit. When coal from the mines in Pennsylvania began to be shipped to the Eastern States, first by way of the canals and then by rail, the use of coal in kitchens became more popular, and some kitchens were fitted up with closed fire or coal ranges in place of the open flames. Thus it came about that the modern kitchen coal range gradually superseded the former primitive devices. But in recent years, prudent, and economical housekeepers have not been slow in recognizing the many advantages of cooking by means of gaseous fuel. This is clean, labor saving, of the utmost convenience, and economical, if properly managed. In these days when gas is constantly becoming reduced in price, owing to improved methods of manufacture, while coal is getting scarcer and at the end of each winter or during miners' strikes becomes higher in price, gas cooking ranges are rapidly gaining in favor. Householders who have provided their kitchen with a modern gas range, who also have an auxiliary apparatus, using gas to heat the water in the kitchen boiler, and who have in the laundry the convenient gas sad irons for ironing, need no longer lay in a large supply of coal for the winter and pay the coal bill before the fuel is used ; they can save the bother and annoyance of handling and storing their kitchen fuel. Numerous are the advantages of gas ranges: a gas range requires no coal to be carried up from the cellar, and no ashes to be carried away. A gas range saves time, because it is Development and Progress 275 instantly lighted, the fire is under perfect control, it is quickly adjusted and regulated, it is always ready for use, and no fuel is wasted, for by the turn of a stopcock the gas flame is entirely put out. Gas fuel is also safer than kerosene oil or gasoline. Kitchens fitted up with gas ranges are kept cleaner; there is no soot nor dirt, and in summer time the kitchen can be kept cool and pleasant. Gas ranges also require fewer repairs than coal ranges, and not the least advantage is that they do better cook- ing, roasting, and broiling. To all these reasons is due the recent great activity in the gas stove business, by which the gas com- panies are profiting Many of the modern apartment houses in New York City, in Brooklyn, and in other cities have now kitchens fitted with gas instead of coal ranges. But even for heating, gas is convenient and offers many advantages, particularly in the autumn and spring of the year, when only a moderate heat is wanted, but likewise in zero weather, at which time gas logs in fire places, incandescent gas heaters, gas stoves, gas radiators, etc., are used advantageously to increase or supplement the heat obtained from furnaces or steam boilers. A successful and novel form of gas-heating stove has recently been introduced in Germany, the inventor and manufacturer of which is Professor Junkers, of Aix-la-Chapelle, and Dessau, in Germany. "Should a heating stove necessarily stand on legs?" asked Professor Junkers in one of his interesting pamphlets, describ- ing the new device. He draws attention to the fact that it is difficult to conceive objects, which one has been accustomed from childhood to see in a certain form, being made differently. Whoever thought until now of constructing a gas heating stove of a different form and to place it in a position other than on the floor? True, as long as one was obliged to use heavy and com- pact fuel for heating one could not very well dispense with the solid and strong legs, embodied in the construction of the usual forms of heating stoves. Since however wood and coal are being more and more replaced by gaseous fuel, it does seem unreason- able to hold fast to old traditions and to the clumsy forms of our heating stoves. The Junkers gas-heating stoves are of such form and construe- 276 Gas Piping and Gas Lighting tion that they may be attached to the gas-supply pipe along the wall at any height instead of being placed on the floor. In these stoves cold air is drawn in from the bottom, or from very near the floor line, and passes upward at the rear behind a reflector and thence through a number of flat tubes ascending towards the front of the stove, and after being heated by these tubes, which are surrounded by the hot gases from the burner, the warm air passes out into the room vertically upwards and also forward at the front of the stove. This secures a strong circulation of the air of the apartment, while the downward rays from the reflector tend to warm the floor and the lower strata of air. In this way, a room may be quickly and uniformly heated. There is a complete combustion of the gas, the heat units generated are utilized to best advantage in the heating surfaces, and a very intense heat is produced. The heated gases, after having done their work round the air tubes, pass out at the top through a flue which is connected with some available chimney flue. These stoves are odorless and perfectly sanitary, because there is no chance for products of combustion to escape into the room. The wall, or the wall paper at the back of the stove, do not become warm, because cold air ascends at the back of the stove. The stoves are quickly and easily installed by connecting a gas coupling at the top of the stove with a gas pipe dropped from the ceiling along the wall. The stove may be placed at any height usually from 12 inches to 20 inches above the floor, and no other wall clamps or fasteners are required. Gas-heating stoves attached to a wall secure a number of advantages compared with the usual forms of gas stoves. In the first place, the installation is simple, and easily and cheaply made. In connecting the old forms of gas-heating stoves it was necessary to cut the gas pipe to exact measure, because the heating stove had to stand on the floor. In passing, it may be remarked that a permanent connection by means of wrought- iron piping is much preferable to a temporary gas-hose con- nection. The new wall stoves are attached only at a single point of the gas service and it is not necessary to measure exactly the distance of the coupling from the floor, because the stove does not stand on the same. Another advantage of considerable importance lies in the sav- ing of floor space. All old forms of gas-heating stoves require Development and Progress 277 a floor space proportionate to their size, and the space between the floor and the stove is rendered useless. The wall stove does not occupy any valuable space in the room, but can be attached at any part of the wall wherever desired, and while it gives a large amount of heat the size of the stove is compara- tively small. Another advantage of wall stoves is one of sanitary impor- tance. With the old forms of gas stoves the floor underneath them could not readily be cleaned. Dust and dirt and unhealth- ful matters accumulated beneath them, and yet the old form of stove draws the air from the very part of the floor which cannot be cleaned, causing the dust to be drawn up and burned on the surface of the stove, producing an annoying odor, which can- not help being disagreeably felt by the occupants of the apart- mant, and which is surely unhealthful. By hanging the stove against the wall at some height above the floor, it is possible to clean the entire floor and therefore accumulations of dirt and dust cannot occur. A further advantage consists in the more uniform warming of the apartment. With all forms of stoves which stand on legs, the floor underneath and at the sides of the stove does not receive any heat radiation and therefore remains cold. The reflector of the wall stove causes the floor near and in front of it to be warmed, and in this way the lower strata are also warmed. This in turn has a tendency to warm the air of the room more uni- formly. The appearance of these new stoves is quite different from that of the older gas stoves standing on a floor, and it is pos- sible to design and construct a large variety of quite ornamental, novel, and pleasing forms. Gas-heating stoves, in general, have the following advantages as compared with coal stoves. They require no attendance, are quickly lit by the use of a match and can be quickly and easily regulated after being lighted. The full heat production is utilized almost immediately after lighting the stove so that the room can be quickly warmed, whereas in using a coal stove a great deal of time must necessarily pass before it gives off a gooi heat. When the room is sufficiently warm, the produc- tion of further heat may be quickly and completely stopped in a gas-heating stove, while this cannot be done with any coal or wood stove. Relatively speaking, the running expenses are lower for gas-heating stoves, because the heat produced by the 278 Gas Piping and Gas Lighting burner is very largely utilized, whereas much of the heat gen- erated in coal stoves is lost by going directly up the chimney. For temporary use gas heating may be cheaper than heating by coal, even where the price of the fuel is higher. Many draw- backs and disadvantages of coal stoves are done away with by using gas stoves, such as the creation of dirt, smoke, soot, the cleaning of the stoves and chimneys, the storing and transpor- tation of the fuel, and the removing of the ashes. Another recent invention in which gas instead of coal is used as fuel is a gas-burning furnace. Finally, gas is advantageous as fuel for operating small motors, such as house pumps, etc., and it is likewise used for clothes dryers, for heating laundry irons, and for warming the water used in lavatories and bathtubs, as well as in kitchen and laundries, not to mention innumerable minor industrial pur- poses, in which gas is used, partly for fuel and partly for power purposes. CHAPTER XXVII. BIBLIOGRAPHY OF GAS LIGHTING. English Books, Matthews. Historical Sketch of Gas Lighting. London. 1832. Peckston. Practical Treatise on the Manufacture of Gas. London. 1841. Cozens. The Gas Consumer's Ready Reckoner. London. 1860. Kidd. History of Gas. 1865. Richards. The Gas Consumer's Guide. London. 1866. Clegg. On the Manufacture of Coal Gas. London. 1868. Wilkins. How to Manage Gas. London. 1868. Campbell. Gas Light Manual. Management of Gas for Domestic Pur- poses. London. 1870. Wood. Gas Lighting. Lewes. 1872. Richards. Treatise on the Manufacture of Coal Gas. London. 1877. Bevan. British Manufacturing Industries. London. 1877. Wilson. Common Sense for Gas Users. London. 1878. King. Treatise on Coal Gas. London. 1879. 3 vols. Bower. Gas and Water Engineer's Book of Reference. St. Neots. 1880. Denny. Cooking and Heating by Gas. Dunbarton. 1881. Sugg. The Domestic Uses of Coal Gas. London. 1884. Galton. On Ventilation, Warming and Lighting. London. 1884. Meniman. Gas Burners, Old and New. London. 1884. Melson. Gas Consumers' Manual. London. 1884. Hughes and Richards. Gas and Gas Works. London. 1885. Black. Gas Fitting. London. 1886. Newbigging. Devices for Gas Illumination. London. 1886. Sugg. Modern Street Lighting. London. 1887. Dune. Old Lights and New. London. 1887. Thwaite. Gaseous Fuel. London. 1889. Newbigging. Handbook for Gas Engineers and Managers. London. 1889. (There are later editions.) Shaw. Practical Hints on Gas Consumption. Huddersfield. 1891. Fletcher. Coal Gas as a Fuel. Warrington. 1891. Fletcher. The Commercial Uses of Coal Gas. Warrington. 1891. Webber. The Science and Practice of Lighting. London. 1892. Wright. Coal Gas and its Uses. Birmingham. 1892. Light without a Wick. By " A.M." Glasgow. 1892. Chilton-Young. Metal Working for Amateurs. (Gas Piping.) London. 1893. 279 280 Gas Piping and Gas Lighting Cripp. Gas Literature: English and Foreign. London. 1894. (Appendix to Transactions of Incorporated Institute of Gas Engineers.) Sugg. Gas Engineers' Pocket Almanac. London. 1894 and 1895. O'Connor. The Gas Engineer's Pocketbook. London. 1898. Hasluck. Practical Gas Fitting. London. 1900. Newbigging. A Hundred Years of Gas Enterprise. London. 1901. Grafton. A Handbook of Practical Gasfitting. London. 1901. Hills. Gas and Gas Fitting. London. 1902. The Gas Fitter's Guide. Grove and Thorp. Chemical Technology. Vol. III. Gas Lighting. Johnston. Gas Lighting and the best Method of applying it to Buildings. Ferrier. Gas Economy. Gas and all about it: A Gas Consumer's Vademecum. W. H. Y. Webber. Town Gas and its Uses for the Production of Light, Heat and Motive Power. London and New York. 1907. Hole, W. Distribution of Gas, with numerous Tables, Diagrams and Figures. London. 1907. Lewes, Vivian B. Liquid and Gaseous Fuels. London. 1907. American Books. Perkins. Gas and Ventilation. Philadelphia. 1869. Cathels. Gas Consumers' Manual. Montreal. 1873. Galloway. Gasfitters' and Plumbers' Guide. Philadelphia. 1875. American Meter Co. Gas Engineer's Pocket Almanac 1878. Moore. The Gas Consumer's Guide. Boston. 1885. Humphreys. Gas as a Source of Light, Heat and Power. New York. 1886. James. Relation of the Modern Municipality to the Gas Supply. 1886. Mooney. The American Gas Engineer's arid Superintendent's Handbook. New York. 1888. Bemis. Municipal Ownership of Gas in the United States. 1891. D. McDonald & Co. Gas Engineer's and Superintendent's Pocket Annual. Albany, N. Y. 1891. Jonesbury. Lamp primer. Columbus, O. 1893. Lomax. The Evolution of Artificial Light. Omaha, Neb. 1893. American v Meter Co. Gas Engineer's and Superintendent's Pocket Almanac. 1893. Gerhard. Gas Lighting and Gas Fitting. New York. 1894. Lawler. Hot Water Heating, Steam and Gas Fitting. New York. 1895. Hughes and Gray. Practical Gas Fitting. New York. 1896. Martin. The Story of a Piece of Coal. New York. 1896. Harland. The Comfort of Cooking and Heating by Gas. New York. 1898. Dunbar. The Gas Fitter's Question Book. Boston. 1898. The United Gas Improvement Co. Specifications for House Piping. Philadelphia. 1901. Bibliography of Gas Lighting 281 Appleton's Universal Encyclopaedia. Article on Gas. Russell Sturgis. Dictionary of Architecture. Vol. 2. Article on Gas Lighting by W. P. Gerhard. 1901. Bell. The Art of Illumination. New York. 1902. Cravath and Lansing. Practical Illumination. New York. 1907. Latta. Handbook of American Gas Engineering Practice. New York. 1907. Gerhard. The Superintendence of Piping Installations in Buildings. New York. 1907. Gerhard. The American Practice of Gas Piping and Gas Lighting in Buildings. New York. 1908. French Books. Payen. L'Eclairage au Gaz. Paris. 1867. E. Jourdan. L'Eclairage au Gaz. Le Mans. 1869. Monnier. Aide-Me*moire pour le Calcul des Conduites de Distribution du Gaz. Paris. 1876. Figuier. L'Art de L'ticlairage. Paris. 1887. Thomas. Histoire de L'Eclairage. Paris. 1890. Guide du Consommateur de Gaz. Marseilles. 1891. Mont-Serrac et Brisac. Le Gaz et ses Applications. Paris. 1892. M. Leaute. L'Eclairage. Paris. Galine. Traite General de L'Eclairage. Paris. 1894. German Books. Rutter. Gasbeleuchtung. (Translated into German.) Leipzig. 1835. Schmitz. Populaeres Handbuch der Gasbeleuchtung. Koeln. 1839. Brown. Vademecum fuer Gasconsumenten. Stuttgart. 1853. Hartmann. Die Kunst der Gebaeude-, Zimmer-, und Strassen- Erleuchtung. Weimar. 1853. Schmidt. Die verschiedenen Substanzen, welche gegenwaertig zur Beleuchtung angewendet werden. Weimar. 1861. Schreiber. Das Heizen und Kochen mit Gas. Weimar. 1861. Jahn. Gasbeleuchtung und die Darstellung des Leuchtgases. Leipzig. 1862. Bolley. Das Beleuchtungswesen. Braunschweig. 1862. Hartmann. Fortschritte und Vervollkommnungen der Gasbeleuchtung. Mit Atlas. Weimar. 1864. Bischoff. Gasbeleuchtung. Berlin. 1864. Koehler. Gas-Meister fuer Jedermann. Leipzig. 1865. Raible. Die Gasuhr. Stuttgart. 1865. Knapp. Lehrbuch der Chemischen Technologie. Braunschweig. 1865. Winter. Neueste Fortschritte ueber das Leuchtgas. Wien. 1866. Jahn. Collektaneen ueber Gasbrenner. Dresden. 1868. Jahn. Das Gas Buechlein. Dresden. 1868. 282 Gas Piping and Gas Lighting Das Gas Buechlein des Herrn Jahn, Beleuchtet. Eine Warnimg fuer Gaskonsumenten. Frankfurt a/M. 1868. Offener Brief an Herrn Jahn. Frankfurt a/M. 1868. Weber. Luft und Licht in menschlichen Wohnungen. Darmstadt. 1869. Diehl und Ilgen. Gasbeleuchtung und Gasverbrauch. Iserlohn. 1871. Blochmann. Geschichte der Gasbeleuchtung. Dresden. 1871. Blochmann. Vortraege ueber Beleuchtung. Dresden. 1873. Ilgen. Die Gas Industrie. Leipzig. 1874. Tieftrunk. Gasbeleuchtung. Stuttgart. 1874. Quaglio. Gas Industrie. Wien. 1876. Perl. Beleuchtungs-Stoffe. Wien und Leipzig. 1876. Fischer. Die Petroleum Lampe. Weimar. 1876. Mendlik. Gasbeleuchtung. Budapest. 1879. Mueller. Beleuchtungsgegenstaende. Berlin. 1879. Schilling. Handbuch fuer Gasbeleuchtung. Muenchen. 1879. Mit Atlas. Schaar. Steinkohlen-Gasbereitung. Leipzig. 1880. Strott. Leuchtmaterialien. Holzminden. 1880. Mueller. Gasbeleuchtung. Wien, Pest und Leipzig. 1881. Fisher. Die Hochbau-Konstructionen : Handbuch der Architektur. III. Teil, Vierter Band. Kuenstliche Beleuchtung der Raeume. Darmstadt. 1881. Schaar. Kalender fuer Gas- und Wasserfach-Techniker. Muenchen. Published annually. Heinzerling. Petroleum und Leuchtgas. Halle a. S. 1885. Wobbe. Verwendung des Gases zum Kochen, Heizen und in der Indus- trie. Muenchen. 1885. Cohn. Beleuchtungswerth der Lampenglocken. Wiesbaden. 1885. Salomons. Winke fuer Gas Consumenten. Mainz. 1885. Coglievina. Leuchtgas als Waermequelle. Wien. 1885. Ramdohr. Leuchtgas als Heizstoff. Halle a. S. 1887. Muchall. A-B-C- des Gasconsumenten. Wiesbaden. 1889. Coglievina. Gas-Installation. Wien, Pest und Leipzig. 1889. Brown und Schaar. Vademecum fuer Gasconsumenten. Stuttgart. 1890. Coglievina. Praktischer Rathgeber fuer Gas-Consumenten. Halle. 1891. Pataky. Installateur-Kalender 1891. Berlin. Thenius. Fabrikation der Leuchtgase. Wien, Pest und Leipzig. 1891. Aschner. Der Gasinstallateur. Berlin. 1891. Maerz. Leitfaden fuer Gas-Konsumenten. Leipzig. 1892. Niemann. 1st Heizen und Kochen mit Gas noch zu theuer? Dessau. 1892. Coglievina. Das Gas als Brennstoff. Muenchen. 1892. Schilling. Neuerungen auf dem Gebiete der Erzeugung und Verwen- dung des Steinkohlen-Leuchtgases. Muenchen. 1892. Oechelhaeuser. Die Steinkohlengasanstalten als Licht-, Waerme- und Kraft-Centralen. Dessau. 1892. Lieckfeld. Aus der Gasmotoren-Praxis. Muenchen und Leipzig. 1893. Bibliography of Gas Lighting 283 Toepfer. Der praktische Gasschlosser. Weimar. 1893. Schaefer. Die Kraftversorgung der deutschen Staedte durch Leucht- gas. Muenchen und Leipzig. 1894. Homann. Die aichfaehigen Gasmesser-Constructionen. Muenchen. 1894. Pfeiffer. Das Gas. Mit Atlas. Weimar. 1896. Asche. Verwendung des Gases zu Koch- und Heiz-Zwecken. Wien. 1896. Strache. Das Wassergas: seine Herstellung u. Verwendbarkeit. Leip- zig und Wien. 1896. Steude. Die Literatur des Gas- und Wasserf aches. Muenchen. 1896. Handbuch der Hygiene. Dr. Th. Weyl. IV. Band. Bau- und Woh- nungs-Hygiene. Erste Abteilung: Die Beleuchtung. Prof. Weber. Die Gasbeleuchtung. Rosenbaum. Jena. 1896. Der Staedtische Tiefbau. Geh. Baurat Prof. Dr. Eduard Schmitt. Band IV. Die Versorgung der Staedte mit Leuchtgas. Niemann. 3 Hefte. (2 Published, 1 in Preparation.) 1897. Beigel. Das Leuchtgas u. seine Bedeutung als Waermequelle fuer den Haushalt. Cannstadt. 1898. Lux. Gas und Elektrizitaetswerke in Deutschland. Leipzig. 1898. Olshausen. Elektrolytische Zerstoerung von Rohrleitungen durch Erdstroeme. Berlin. 1899. Schollmeyer. Wie Beleuchte ich am Zweckmaessigsten und Billigsten Meine Wohnung und Geschaeftsraeume? Berlin. 1899. Geitel. Wassergas und seine Verwendung in der Technik. Berlin. 1899. Pietrkowski. Was muss man vom Modernen Beleuchtungswesen wissen? Berlin. 1900. Frenzel. Gas und seine moderne Anwendung. Wien und Leipzig. 1902. Schaeffer. Einrichtung und Betrieb eines Gaswerks. 1902. Lummer. Die Ziele der Leuchttechnik. Muenchen u. Berlin. 1903. Schopper. Die Gasgluehlicht-Beleuchtung. Leipzig. 1903. Kuckuk. Der Gasrohrleger. und Gaseinrichter. Muenchen und Berlin. 1904. Handbuch der Architektur. Dritter Teil, Band IV. Kuenstliche Beleuchtung der Raeume. Baukunde des Architekten. Erster Band, Zweiter Teil. Beleuchtung, insbesondere mit Gas. Schopper. Die Gasgluehlicht-Beleuchtung. Leipzig. 1904. Twistet. Wasser-, Licht-, und Kraft-Versorgung kleiner Stadte. Koenigsberg. 1904. Pettendorfer. Gas in Hause. Ueber Einrichtungen zur Verwendung des Gases fur Beleuchtungs-, Koch - und Heizzwecke. Miinchen. 1905. Briisch. Die Beleuchtungs- Arten der Gegenwart (Sammlung " Aus Natur und Geisteswelt ") Leipzig. 1906. Schaefer. Warmwasser- Versorgung ganzer Hauser durch selbstthatige Erhitzer mit Gasfeuerung. Miinchen. 1906. Schaefer. Kein Haus ohne Gas. Miinchen. 1906. 284 Gas Piping and Gas Lighting Schaefer. Die angebliche Gefahrlichkeit des Leuchtgases im Lichte statistischer Thatsachen. Miinchen. 1906. Schaefer. Das Gas im biirgerlichen Hause. Miinchen. 1907. Heim. Gas oder Elektrizitat ? Hannover. 1907. Bloch. Grundziige der Beleuchtungs-Technik. Berlin. 1907. Schaar. Kalender fur Gas und Wasserfach-Techniker. Miinchen, Pub- lished annually. American Reports. Raymond. Illuminating Gas: Its History and its Dangers. From 10th Annual Report State Board of Health of New Jersey. Commissioner of Health of Brooklyn. Report on Illuminating Gas. 1883. Special Consular Report. Gas in Foreign Countries. Washington. 1891. Committee of Franklin Institute. Report on the Holophane Globes for Effecting the Better Diffusion and Distribution of Artificial Light. April, 1898. Reports of Gas and Electric Light Commissioners of Massachusetts, Boston, annually. Proceedings of American Gas Light Association. Annual Reports. English and American Pamphlets. Ohren. Advantages of Gas for Cooking and Heating. 1875. Wood. Illuminating Gas in its Relations to Health. Cambridge. 1877. Francis A. Walker. International Exhibition, 1876. Reports and Awards. Group XIV. Philadelphia. 1878. Fletcher. The Use of Gaseous Fuel. 1880. London. Hartley. Observations on Glass as an Obstructor and Reflector of Artificial Light. London. 1881. Crompton. Artificial Lighting in Relation to Health. London. 1881. Hartley. Calorific Power of Coal Gas. 1881. Field. Solid and Liquid Illuminating Agents. London. 1883. Fahie. Electric Lighting considered from a Sanitary Point of View. London. 1884. Dixon. The Use of Coal Gas. London. 1885. Sugg. Roasting and Cooking by Gas. 1885. Dixon. The Use of Coal Gas. London. 1885. Sedgwick and Nichols. The Relative Poisonous Effects of Coal and Water Gas. Boston. 1885. Gregory. Handbook on Gas. New York. 1886. Colson. Gas Cooking Stoves on Hire. Leicester. 1886. Rutter. Advantages of Gas. Brighton. 1887. Fletcher. Flame and Smoke. London. 1888. Fletcher. Coal Gas as a Labor Saving Agent. Warrington. 1888. United Gas Improvement Co. The Lowe Water Gas Apparatus. Phila- delphia. 1890. Bibliography of Gas Lighting 285 Bryant. Oil or Gas for lighting our Homes. The Use of Gas Stoves in our Homes. 1890. Lewes. Gaseous Illuminants. London. 1891. Lewes. The Generation of Light from Coal Gas. London. 1893. Clowes. The Detection and Estimation of small Quantities of Inflam- mable Gas or Vapour in the Air. London. 1894. Lewes. The Use of Gas for Domestic Lighting. London. Stott. Architect's and Surveyor's Handbook of Gasfitting. London. 1895. Gas Exposition at Madison Square Garden. New York. 1897. Lewes, Vivian B. The Use of Gas for Domestic Lighting. London. 1897. Nicolls. The Spirit of Coal. New York. 1897. Lummer. Light and its Artificial Production. Washington. 1898. Lighting, Heating and Cooking. London. A General Systematic Plan for Detecting Leaks in Gas Mains. Colson. Economy and other Advantages of Cooking by Gas. Leicester. Smith. A Study of Certain Shades and Globes for Electric Lights. Part I, 1900. Part II, 1902. Technology Quarterly. Smith. Some Notes on Several Types of Mantles for Incandescent Gas Burners. Technology Quarterly. 1902. Peebles. How to Burn Gas. Edinburgh. Newbigging. Illuminating Power and Illuminating Effect. Bibbins. Fuel Gas for-Internal Combustion Engines. Cassier's Magazine. Lansingh. Engineering of Illumination. Reprint from Journal Western Society of Engineers. Vol. VIII. 1903. Enos Co. A Renaissance in Gas Lighting. New York. 1905. Nernst-Lamp Co. The Lighting of Public Buildings. Pittsburgh. 1906. Robb. Instructions for Gas Distribution Employees. New York. 1906. " Lux " The Art of Lighting. Pittsburgh. 1907. Gas Logic. A Monthly Magazine of Enlightment and Progress. Pub- lished by the Consolidated Gas Company, New York. Vol. I, 1906. Vol. II, 1907. The Illuminating Engineer. A monthly magazine. Vol. I, 1906. Vol. II, 1907. Bulletins of Engineering Department of the National Electric Lamp Association. No. 1-7. 1907. Largely about electric incandescent lamps, but No. 7, of June 1, 1907, gives general data on illumination. Six Pamphlets Issued by the Holophane Glass Co. Light v. Illumination. The Lighting of the Home. The Lighting of Hotels and Clubs. The Lighting of Large Buildings, Offices, and Stores. The Lighting of Theaters and Public Halls. The Lighting of Churches, Schools, Libraries, and Hospitals. Stott, Jas. Hints to Gas Consumers. London. 286 Gas Piping and Gas Lighting Pamphlets by Wm. Paul Gerhard, C. E. Notes on Gas Lighting and Gas Fitting. New York. 1890. Hints to Gas Consumers on the Proper Use and Management of Gas. 1892. Artificial Illumination. 1893. New York. The Use of Gas for Heating and Cooking. New York. 1894. On Gas Burners, Gas Pressure Regulators and Governor Burners, Gas Globes and Globe Holders, and Gas Fixtures. 1894. The Relations Between Gas Companies and Consumers. 1894. Illuminating and Fuel Gas. 1900. Suggestions for the Proper Arrangement o f Gas Piping Work. 1900. German Pamphlets and Reports. Hempfing. Ueber Gasbeleuchtung. Marburg. 1866. Nachtsheim. Gas und Elektrische Beleuchtung. Wien. Kein Haus ohne Gas. Berlin und Miinchen. Six Editions. Cohn. Ueber Kuenstliche Beleuchtung. Braunschweig. 1883. Quaglio. Fortschritte in der Gasindustrie. Berlin. 1885. Die Elektrische Beleuchtung des kgl. Hoftheaters in Miinchen. Central- blatt fuer Elektrotechnik. 1885. Pettenkofer. Ueber Vergiftung mit Leuchtgas. Miinchen. Mehlhausen. Ueber Kuenstliche Beleuchtung. Berlin. 1885. Mohrmann. Ueber die Tagesbeleuchtung Innerer Raeume. Berlin. 1885. Osthues. Fabrikation und Verwendung des Wassergases. Dortmund. 1885. R. Goehde. Ueber die Neuesten Fortschritte in der Verwendung des Leuchtgases zum Kochen, etc. Gewerbeschau. 1893. Aschner. Gluehlicht mittelst Gas Erzeugt. Leipzig. 1893. Dr. Meidinger. Gas-Heizung u. Gas-Oefen. Badische Gewerbezeitung 1894. Hartmann. Die Fortschritte der Gas -und der elektrischen Beleuch- tung. Berlin. Arche. Ueber neue Gas-Schuloefen. Triest. 1895. Arche. Verwendung des Gases zu Heiz- und Koch-Zwecken. Wein. 1896. Verwendung des Gases zu Heiz- und Kochzwecken. Wien. 1896. Meidinger. Gas oder Elektrizitaet? Karlsruhe. 1898. D. Coglievina. Gasdruck und Gasverbrauch. Anleitung zur richtigen Konstruktion, Aufstellung und Handhabung von Gasheiz-Apparaten. Miinchen. 1907. Die Verwendung von Spiritus im Haushalt. Herausg. von der Centrale fiir Spiritus Verwertung. Berlin. 1907. Miniatur-Bibliothek - No. 176 Moderne Beleuchtung- Allgemeines-Kerzen u. Lampen. 177 Moderne Beleuchtung-Beleuchtung durch Gase. 178 Moderne Beleuchtung-Das elektrische Licht. 389 Moderne Beleuchtung-Herstellung des Leuchtgases. 434 Auer's Osmiumlampe-Bremer Lampe. Bibliography of Gas Ligliting 287 Miniatur-Bibliothek No. 221 Nernst-Lampe-Auer's elektrisches Gliihlicht. 265 Tesla-Licht, Moore's Beleuchtung, Press gas, Luftgas. 234 Azetylen. General Articles on Gas Lighting. D. Coglievina. Increased Gas Consumption Its Cause and Preven- tion. The American Engineer. 1886. A Perfect Gas Regulator. The American Architect. 1890. J. H. Troughton. Consumers' Fittings. American Gas Light Journal. 1892. W. H. Anson. Should Gas Companies do all Gas Fittings ? The Ameri- can Architect. 1892. The Hero of Gas. American Architect. 1892. G. A. Allen. Discrimination by Gas Companies in the Treatment of their Consumers. Ohio Gas Light Association. 1893. D. McDonald. A Talk on Natural Gas. Engineer's and Architect's Association. 1894. Gas Piping for Buildings. Engineering Record. 1894. The Planning and Lighting of the Modern House. Journal of Gas Light- ing. 1894. J. P. Gill. Distribution of Gas. American Gas Light Journal. 1894. H. Hopkins. The Evolution of Artificial Light. Plumbing and Gas Fitting. 1896. D. Macfie. Gas Control from Meter to Burner. American Gas Light Journal. 1897. Cappelen. Municipal Lighting in the United States. 1897. W. Hallock. Diffused Illumination. Progressive Age. 1898. W. Eckstein. Interior Lighting. American Architect. 1898. Gas Pipe Engineering. American Gas Light Journal. 1899. Gas Piping Topics. American Gas Light Journal. 1899. Manufacture of Illuminating Gas. Scientific American. 1900. The Manufacture of Coal Gas. Scientific American. 1900. Dr. W. H. Greene. Prismatic Lighting for the Illumination of Dark Interiors. American Architect. 1900. F. Erismann. Hygienic Lighting. Progressive Age. 1900. W. Fletcher. The Inventor of Gas Lighting. Engineering Magazine. H. Crew. On the History of Our Ideas Concerning Illumination. J. R. Bibbins. Fuel Gas for Combustion Engines. Cassier's Magazine. Shepardson. Artificial Lighting. 1897. Journal of the Association of Engineering Societies. Greenough. Modern Gas Engineering. 1898. Journal of the Associa- tion of Engineering Societies. Vincent, G. I. Standard Methods^ in Service, Meter, Appliance and House Fitting. American Gas Light Journal. July, 1907. 288 Gas Piping and Gas Lighting Gas Meters. Autobiography of a Measurer of Light. Progressive Age. 1886. C. W. Hinman. Some Facts About the Gas Meter. American Gas Light Journal 1886. The Alleged Vagaries of the Gas Meter. American Gas Light Journal. 1886. G. Keillor. How to Keep down Complaints and Grumbling Amongst Consumers. Journal of Gas Lighting. 1892. F. Egner. An Unpopular Subject Popularly Treated. American Gas Light Journal. 1893. New Prepayment Meters and Gas Lighters. Journal of Gas Lighting. 1894. W. R. Herring. How to Burn and How to Save Gas. Gas Engineer's Magazine. 1895. The Explosion of Gas Meters. The Metal Worker. 1900. H. S. Wynkoop. Gas and Gas Meters. Popular Science Monthly. 1905. W. McDonald. History of the Gas Meter. Progressive Age. Cooking by Gas. Dr. Macadam. On the Sanitary Aspects of Cooking and Heating by Gas. Journal of Gas Lighting. 1882. Experiments with Gas Stoves. The Metal Worker. 1893. W. W. Goodwin. Advantages of Gas over Coal for Cooking and Heating Purposes. American Gas Light Journal. 1893. W. H. Manwaring. Gas Cookers. Progressive Age. 1893. Th. Fletcher. The Use of Coal Gas for Domestic Purposes other than Lighting. Hygiene. 1894. Rules for Gas Piping. W. B. Gray. Practical Gas Fitting. The Metal Worker. 1890. J. Lyne. Gas Fittings and Their Supply by Gas Undertakings. Gas Engineer's Magazine. 1893. J. W. Hughes. Gas and Gas Fitting. The Metal Worker. 1894. H. O'Connor. Practical Gas Fitting from Main to Burner. Building World. 1895. The Delivering Capacity of Gas Mains. Gas World. 1896. L. T. Wright. Diagrams showing Delivery of Gas by Pipes and Loss of Pressure at Point of Discharge. Gas World. 1896. W. Grafton. Determining the Size of Gas Pipes. American Gas Light Journal. 1899. Practical Gas Fitting. Progressive Age. 1900. P. Thirman. Proper Supervision of Gas Fittings. Light, Heat and Power. Bibliography of Gas Lighting 289 Gas Burners. E. Stein. Can Large Gas Burners Successfully compete with Arc Electric Light? American Gas Light Journal. 1886. J. A. Faux. Gas Burners. Ohio Gas Light Association. 1892. Th. Travers. Gas Burners. A Suggestion. American Gas Light Journal. 1893. Economical Use of Gas for Light. Progressive Age. Accidents with Gas and Dangers of Gas Lighting to Health. L. Stieringer. The Evolution of the Fixture Art and Decorative Illumi- nation. Electrical Review. 1891. Fatal Gas Accidents. The Queen. 1893. I. Butterworth. Ninth Annual Meeting of the Ohio Gas Light Associa- tion. Columbus, O. Progressive Age. 1893. Governor Burners. Bayles. Hazard of Gas Leakage. 1902. Insurance Engineering. Articles on Gas by Wm. Paul Gerhard. Notes on Gas Lighting and Gas Fitting. Philadelphia. Builder and Decorator. 1889. Notes on Gas Lighting and Gas Fitting. American Gas Light Journal. 1890. Hints to Gas Consumers on the Proper Use and Management of Gas. 1892. Artificial Illumination. New York. 1893. The Relations between Gas Companies and Gas Consumers. Gassier >s Magazine. 1894. On Gas Burners, Gas Pressure Regulators and Governor Burners, Gas Globes and Globe Holders, and Gas Fixtures. Journal of Franklin Institute. 1894. Municipal Rules and Regulations Regarding Gas Piping and Gas Fitting in the City of Munich, Germany. Light, Heat and Power. 1894. Accidents with Gas. American Architect. 1899. Dangers of Illuminating and Fuel Gas. Progressive Age. 1900. The Development and Progress of the Gas Industry in Greater New York. Engineering Review. 1900. Illuminating and Fuel Gas. Its Dangers to Health and How to avoid Them. Cassier's Magazine. 1900. The Superintendence of Sanitary, Hydraulic and Gas Piping Work in Buildings. Architects and Builder's Magazine. 1900. Suggestions for the Proper Arrangement of Gas Piping Work. Science and Industry. 1900. The Use of Gas for Cooking and Heating. Metal Worker. 290 Gas Piping and Gas Lighting A PARTIAL BIBLIOGRAPHY OF ACETYLENE ILLUMINATION. English Books. G. F. Thompson. Acetylene Gas: Its Nature, Properties and Use; also Calcium Carbide: Its Composition, Properties and Method of Manu- facture. London. 1898. G. F. Thompson. Acetylene and Calcium Carbide. Liverpool. 1898. W. E. Gibbs. Lighting by Acetylene: Generators, Burners and Electric Furnaces. New York and London. 1898. G. G. Pond. The Application of Acetylene Illumination to Country Homes. Bulletin No. 57, Department . of Agriculture, Pennsylvania. 1900. (Contains Bibliography.) Leeds and Butterfield. Acetylene : Its Generation and Use. London. 1903. Turner. Acetylene Gas: How to Make and Use it. London. 1904. J. A. Matthews. Review and Bibliography of the Metallic Carbides. Washington. German Books. F. Marsden. Zur Kenntniss des Acetylens. Heidelberg. 1892. G. Pelissier. Praktisches Handbuch der Acetylenbeleuchtung und Calciumcarbidfabrikation. Transl. by A. Ludwig. Berlin. 1897. K. Visbeck. Calcium Carbid und Acetylen. Herstellung und Verwen- dung derselben. Halle. 1897. Dr. Jovan P. Panaotovic. Calcium Carbid und Acetylen, in Vergangen- heit, Gegenwart und Zukunft. Leipzig. 1897. F. Grover. Ueber den Druck und die Explosionskraft von Acetylen- luftmischungen. Leeds. 1898. Froelich und Herzfeld. Stand und Zukunft der Acetylenbeleuchtung. Berlin. 1898. Dommer. Calciumcarbid und Acetylen. Muenchen und Leipzig. 1898. H. F. B. Schaefer. Kalender fuer Acetyleniker fuer das Jahr 1899. Berlin. 1898. Fr. Peters. Fortschritte der angewandten Electrochemie und der Acetylen - Industrie im Jahre 1898. Stuttgart. 1899. Dr. Ludwig. Fueher durch die gesammte Calciumcarbid und Acetylen- Literatur. Berlin. 1899. Ahrens. Das Acetylen in der Technik. Stuttgart. 1899. Scholtze. Ueber Acetylenbeleuchtungsanlagen. Leipzig. 1901. F. Liebetanz. Hilfsbuch fuer Installation von Acetylenbeleuchtungs- Anlagen. Leipzig. (No date.) Bibliography of Gas Lighting 291 French Books. F. Dommer. L'Incandescence par le Gaz et le Petrole. L'Acetylene et ses Applications. Paris. 1896. G. Dumont et E. Hubon. Historique, Proprie*tes, Fabrication, Applica- tions de 1' Acetylene. Paris. 1896. C. de Perroclil. Le Carbure de Calcium. Paris and Marseilles. 1896. R. Pictet. Le Carbite, nouveau procede pour sa fabrication. Geneve. 1896. R. Pictet. L'Acetylene, son passe, son present, son avenir. Geneve. 1895. J. Reyval. L'Eclairage a 1'Acetylene. Construction pratique et installa- tion a la portee de tous d'un appareil pour cet eclairage. Paris. 1896. H. Moissan. Le four clectrique. Paris. 1897. F. Drouin. L'Acetylene. Paris. 1897. G. Dumount. L 'Acetylene et son application a 1'eclairage. Conference faito a Annecy. 1897. G. Gastine. L'Acetylene et ses applications a 1'eclairage. Conference faite a la Societe scientifique industrielle de Marseilles. 1897. L. Mathet. L' Eclairage a 1'Acetylene. Construction pratique et instal- lation a la portee de tous d'un appareil pour cet eclairage. Paris. 1897. G. Pelissier. L'Eclairage a 1'Acetylene. Historique, fabrications, appar- eils, applications, dangers. Paris. 1897. J. Reyval. Une Revolution dans 1'Eclairage domestique. Paris. 1897. C. de Perrodil. Le Carbure de Calcium et Acetylene. Paris. 1897. E. Capelle. L'Eclairage a 1'Acetylene. Paris. 1898. L. Gastine et Saint Paul. Eclairage. Paris. 1898. P. Hubert. Album de 1'Acetylene. Paris. 1898. J. Lefevre. Carbure de Calcium et Acetylene. Paris. 1898. J. Reyval. Gare les Explosions! L'Eclairage des velos a 1'acetylene. Conseils aux cyclistes. 1898. J. Reyval. L'Eclairage de demain: L'Acetylene. Paris. 1898. English Articles. Cheap Illuminating Gas. Discovery of a New Method of Manufacture. The Evening Post. New York. March 9, 1895. Some Notes on the History of Electro-Smelting. Progressive Age. July, 1895. The Illuminating Value of Acetylene. Progressive Age. August, 1895. Acetylene. Lecture by W. W. Goodwin. Progressive Age. November, 1895. The Poisonous Properties of Acetylene. Progressive Age. March, 1896. Notes on the Use of Acetylene Gas as an Illuminant. Progressive Age. March, 1896. An Acetylene Standard for Photometry. Progressive Age. The Explosiveness of Acetylene. 292 Gas Piping and Gas Lighting Carbide of Calcium. Acetylene Gas. Contains Bibliography. Pro- gressive Age. April, 1896. Ed. Hospitaller. Carbide of Calcium and Acetylene and their Applica- tions. Progressive Age. May, 1896. Berthelot and Violle. Studies of the Explosive Properties of Acetylene. December, 1896. Rules in Regard to the Preparation of Acetylene. Report of Committee of French Scientists and Officials. Progressive Age. January, 1897. Storage of Calcium Carbide and Acetylene. Editorial Comment from the London Chemical Trade Journal. Progressive Age. March, 1897. Restrictions Placed Upon Carbide of Calcium in England. Progressive Age. April, 1897. Acetylene. Discussion before the Berlin Society of Chemical Industry. Cost of Acetylene on Board Ships. Lecture by Vivian B. Lewes. Pro- gressive Age. May, 1897. Recent Foreign Notes on Acetylene. Carburetted Water Gas. Report by Vivian B. Lewes. Professor Oettli. Acetylene Illumination. Professor Clowes. Explosibility of Liquid Acetylene. Progressive Age. May, 1897. C. E. Brown. Recent Researches with Acetylene. Progressive Age. July, 1897. Solutions of Acetylene and Their Explosive Properties. Messrs. Berthe- lot and Violle. Progressive Age. September, 1897. Renouf. The Use of Acetylene. Popular Science Monthly. 1899. Acetylene Gas Catechism. Pan American Company, Buffalo, N. Y., 1901. Acetylene Gas. Architecture and Building. Acetylene as Viewed by Insurance Men. Architecture and Building. Gas of 240 Candle-power. Acetylene. Journal of Gas Lighting. The Acetylene Journal. Chicago, 111. Lansingh, V. R. Illumination of the House by Acetylene. Paper read before the International Acetylene Association. Metal Worker. November, 1907. German Articles. O. C. Reyman. Acetylen. Mitteilungen des Techniker- Verbandes. December, 1898. English Pamphlets. Birchmore. Acetylene Gas. Its History and Utilization. New York. 1897. Rules and Requirements of the National Board of Fire Underwriters for the Construction, Installation, and Use of Acetylene. 1900 and 1901. Bibliography of Gas Lighting 293 List of Acetylene Gas Machines examined under the Rules and Require- ments of the National Board of Fire Underwriters. Revised Quarterly. Acetylene and Its Hazards. The Insurance Press. New York. German Pamphlets. F. Liebetanz. Gesetzliche Verordnungen und Vorschriften der Feuer- versicherungs-Gesellschaften fuer Herstellung und Anwendung von Calciumcarbid und Acetylen. Leipzig. A. Bujard. Ueber Leuchtgas, Gasgluehlicht, und Acetylen. Reprint Stuttgart, INDEX Absorption of light by glass globes, 138. Accidents with gas, 204, 214, 229, 235, 251, 253. Accumulators, 188. Acetylene gas, 180, 185, 186, 198, 242, 244. apparatus for making, 243. burners, special for, 185, 243. discovery of, 242. fittings, 98. lighting, 97, 180, 186, 244. cost of, 188, 189, 190. machines, 185, 186. meters, 154. piping, 97, 98, 99, 100, 101, 186. Acetylene generators, 185, 194, 243. lamps, portable, 180, 186. Advantages of electric lighting, 187. gas as an illuminant, 12, 199. for cooking, 204, 275, 276. heat and power, 16. light, fuel, and power pur- poses, 205. oil lamps, 182. wall gas heating stoves, 276. Air, contamination of, by gas, 5, 9, 127. Air gas, advantages of, 185. carburetted, 1, 241. machine for producing, 184. illumination, 180. machines, 185. piping for, 87, 185. process of making, 184. Air-hole burner, 124. Albo-carbon light, 194. Alcohol, 180. denatured or industrial, 183. lamps, incandescent, 183. All-around keys, use of, 231, 251. American Public Health Association, Report of Committee of, 237. Anniversary of first use of gas, 2. Apartment house kitchens, with gas instead of coal ranges, 275. Appliances, domestic gas burning, 202. for heating water, 204, 205, 274. making acetylene gas, 243. improved gas, 204, 205. pressure reducing, 201. Appliances, (Cont.) showroom for gas, 205. Arc, electric 198, 270. Argand burners, Sugg's improved, 113, 118, 119, 120, 271. Arrangement of gas piping in build- ings, 22, 42. Artificial gas, 1. illumination, requirements of, 179. of interiors, 108. increase of gas pressure in incan- descent lamps, 273. Asphyxiation, 5, 213, 230, 245, 254. Atmospheric changes affecting quality of gas, 8. Automatic gas governors, 130, 131. gas pressure control, 130. regulator burners, 132. safety gas burners, 117, 231, 255. B. Bat-whig burner, 113, 129, 210. "Beacon "lamps, Gleason, 120. Benzine, 180. * Bibliography on gas lighting, 263. Bills, gas, 18, 161, 201, 202, 211, 218. Board of Gas and Electric Light Com- missioners of Mass., statistics of, 254. Board of Gas and Electric Light Com- missioners of Mass., annual re- ports of, 229. Boore burner, 133. Boston Board of Health and Building Commissioner's rules on gas fit- tings, 62. Gas Light Company's rules for gas piping, 61. Bower regenerative lamps, 121. Bracket, gas, 108, 142, 212. lamps, 146. Branches, for chandeliers, 28. sizes of, 29. to side wall burners, 28. Bray burners, 116. Bray's high-power street lamp burner 120. "Brilliant" regenerative lamps, 121. British regulations for gas fittings, 78. Bronner burners, 116. Brooklyn streets, early lighting of, 121. 295 296 Index Brooklyn Union Gas Company, incor- poration of, 269. Brown's regenerative lamps, 121. Building department's control over gas fitters' work, 270. regulations, municipal, 34. Bunsen burner, 112, 227. Bunte, Prof., on incandescent gas lighting, 226, 248, 271. Burner, 111, 203. acetylene, 185, 243. adamas tip, 115. air-hole, 124. aluminum tip, 115. Argand, 113, 118, 271. automatic, 255. safety, 117, 231. gas governor, 130. bats-wing, 113, 129. blowing, 203. Boore, 133. Bray, 116, 129. Broenner, 116, 129. Bunsen, 112. check, 114, 117, 129. cleaners, 115. cleaning and removal of, 204. corrosion in gas, 209. consumption of gas, 77, 128, 129, 131, 135, 200. determination of hourly consump- tion of, 210. duplex gas, 120. enamel tip, 115. fish-tail, 113. flat flame, 113, 116. gas, 108, 203. imported, 266. lighting, 204. Germania Argand, 120. Gleason Argand, 119. governors, 117, 130, 133, 204. high-power, 120. improved, 203, 209. incandescent, 113, 119, 123. gas, 4, 123, 124. mantles, 210. Welsbach, 123. in candle form, incandescent mantle, 175. inverted, 3, 113, 124. Kern, 123. Leoni, 116, 129. Lewis, 123. mantle, 120. manufacture of Welsbach, 272. Morey incandescent gas, 119. multiple, 120. number of, with given size pipe, 36, 94, 96. on chandeliers, height of, 177. Burner, (Cont.) on chandeliers, size of, 171. regenerative, 113, 120, 121, 125, 271. round-flame, 113, 118, 119. safety regulator, 118. self-lighting, 255. self -igniting, 124, 177. Siemens precision, 119. regenerative, 271. Silber, 116. single- jet, 113. size of, 117. slit-union, 113. special open flame, for air gas, 184. steatite tip, 115. Sugg's, 115, 116, 119, 122, 129, 132. improved Argand, 119. London, 119. London improved Argand governor, 119. Winsor, 129. sun, 175. table top, 115, 116, 132. tests, 161. tips, 114, 115. broken lava, 213. twin flat-flame, 120. union-jet, 113, 116. use of bad or cheap, 201. flat-flame, 27V. volumetric governor, 203. ventilating, 125. volumetric, 132, 133. Young American, 129. Butzke regenerative lamps, 121. C. Calcium carbide, 1, 185, 242. Calorific power of gas, 215, 224, 227, 272. Candle form, incandescent mantle burn- ers in, 175. illumination, 111, 180, 264. Candle-power of gas, 217, 224, 225, 269. Candles, 181, 198, 264. electric, 212. in windows, formerly used for light- ing up streets, 264. tallow and spermaceti, 181, 264. wax, stearine and paraffine, 15, 181. Capacities of gas mains, insufficient, 218. meters, 76, 78. pipes, 77. Carbon filament, 180. Carbonic oxide in gas, 213, 229, 244, 248. Carburetted air gas, machine for pro- ducing, 241. hydrogen, 244. water gas, 240. Index 297 Carburetting of gas, 125. Care in use of gas fixtures, 230. of gas fixtures, 225. Car lighting, 124. Ceiling, protection of, 212. Cement, gas fitters', use of, 27. Central Gas Company, starting of, 288. Chandeliers, 108, 142, 144, 146. Check burners, 114, 117, 129. Chicago People's Gas Light and Coke Company's rules and tables for gas fitting, 71, 86. Chimneys, cleaning of, 204. Cincinnati Gas Light and Coke Com- pany's rules for gas fitting, 69. Circulation system, gas, '28. City gas, cost of, 190. Clamond lamps, 123. Clark regenerative lamp, 121. Cleaners for burners, 115. Clegg's table of discharge of gas pipes, 45. Clothes dryers, gas heated, 219. Cluster lights, 142. Coal, 266, 274. heat units in, 17. gas, 1, 239, 240, 267. Combustion, imperfect, 127. products of, in case of illuminating gas, 4. Comparison of gas and water service, 224. Compensating gas meter, 152. Complaints of gas consumers, 159, 200, 214. Composition of coal gas, 240. natural gas, 239. water gas, 241. Concordia burner, 116. Condensation in gas meters, 216. vapor of, 29. Connections for gas meters, 155. heating and cooking fixtures, 252. lead and iron, 155. Consolidated Gas Company formed, 268. of New York, specifications for house piping, 50. Consumers, instructions to gas, 236. Consumption of gas, for different burners, 77. in gas engines, 20. principles of gas, 202. the day, 2, 131, 135. Cornelian globes, 117. Corrosion of service pipes, protection against, 249. Cost of acetylene gas, 188, 189. electric incandescent lighting, 190, 192. gas, 4, 13, 14, 17, 18, 190, 222, 266, 267, 268. gas in London, 223. Cost of, (Cont.) gas in New York City, 223. machines, 186. gasolene gas, 188, 189, 190. illuminants, 13, 14, 92, 190, 191, 192. lighting, data on, 15. natural gas, 83. Country houses, lighting of, 179. " Cromartie " gas lamps, Sugg's, 122. D. Dangers connected with gas distribu- tion, 246. gas fixtures, 250. gas piping in houses, 249. manufacture of gas, 246. use and management of gas, 252. Dangers of fire, 204, 230, 256. gas leaks, 5, 204. illuminating gas, 258. water gas, 237. Dangers to public health from gas, 237, 256. Day consumption of gas, 2, 204. Denver Gas Company, rules of, 68. Detroit Heating and Lighting Com- pany, rules for gas piping of, 95. Development and progress of gas in- dustry, 263. of gas lighting hi New York, 263. Devices, for lighting, 142. self lighting, for gas, 124, 177, 210, 255. Diameters of gas mains and services for acetylene gas, 97. Diaphragm pressure regulators, 131. Discharge of gas pipes, 45, 47. Distribution lines, sizes of, 29. Distribution of gas, 28, 238, 246. system of gas, 250. District of Columbia, gas rules of, 64. Don'ts for gas consumers, 219. Dutch oven, 274. Dwelling-house fires, due to defective lighting apparatus, 212. Dynamo run by kerosene, gasolene or steam engine, 187. water power, 187. E. East River Gas Company, organiza- tion of, 268. Economy in use of gas, 4. Edison electric incandescent lamps, advent of, 270. Efficiency of gas mantles, 272. Electric arc lamps, 198, 270. gas-lighting fittings, 235. illumination, 180, 187. lamps, latest inventions in, 15. lighting, advantages of, 187. 298 Index Electric lighting, cost of 14, 190, 192. plant 187, 188. Electricity or gas? 4, 273. Engineer, illuminating, 110, 173. English pressure regulator, 131. Equitable Gas Light Company started, 268. Era of gas, 199. Escape of gas, 5, 204, 214, 230, 235, 246, 247, 253, 256. European methods of testing gas pipe systems, 106. Exhaust flues for regenerative and ventilating gas burners, 212. Exhibitions, gas, 205, 231. Explosive properties of gas mixed with air, 6, 230, 245, 247. Extension lamps, 176. Filament, carbon, 180. Fires caused by gas escapes, 258. danger of, 204, 236. due to defective lighting apparatus, 212. Fireplace heaters, gas, 205, 207. Fire statistics, 6, 236. Fish-tail burner, 113. Fitters, gas, 205, 207. Fittings, acetylene gas, 98. black, 26. British regulations for, 78. defective, 27, 215. electric gas lighting, 235. galvanized, 26. gas, 26, 38, 41, 204, 230, 255. malleable iron, 26. regulation of Boston Board of Health, 62. regulation of Building Commissioner, 62. regulations of District of Columbia, 64. Fixtures, advice as to type, 142, 145, 170. care and use of, 230, 255. combination, 235. connections for heating and cooking, 252. defective gas, 145, 185, 234. drops, 174. for various rooms, 173, 174, 175, 176, 177. hanging of gas, 144, 171. in hotels and lodging houses, 231. locating gas, 172, 173, 235. location of gas, 212. manufacture of gas, 142. portable gas, 146. rules regarding gas, 23, 30, 108, 142, 146, 147. selection of, 142, 145. Fixtures, (Cont.) side, 172, 173. test of, 250. tightly-jointed, 5. Flames, 111, 126, 201, 209, 213, 216. Flashpoint, of kerosene, 183. Float governors, 134. Flow of gas through pipes, 44, 77, 97. Flues, exhaust, for gas burners, 212. Formula for acetylene gas piping, 98. flow of gas through pipes, 44, 97. Frost, protection of gas services against, 24, 232, 253. Fuel, gas as a, 1, 2, 271, 273, 275, 278. wood as, 266, 273. Fullford regenerative lamp, 121. Fulton Municipal Gas Light Company, forming of, 269. Furnace burning gas, 278. G. Gas accidents, 214, 229, 235, 251. acetylene, 1, 180, 242. air, 1, 87. anniversary of use of, 2. apparatus, 204. appliances, exhibition of, 222. for heating, 205, 222. artificial, 1. as a fuel, 271, 273, 275, 278. as an illuminant, advantages of, 12. asphyxiation, 5, 213, 230, 245. bills, 18, 161, 201, 202, 211, 218. brackets, swinging, 212. burners (see Burner). calorific power of, 215, 224, 227, 272. candlepower of, 217, 224, 225, 269. carbonic oxide in, 229. causing theatre fires, 7. chemical analysis of natural, 82. circulation system, 28. city, 190. coal, 1, 239, 267. commercial use of, 219. companies' inspectors, 270. rules, regulations and tables, 44. company, consolidation and forming of Brooklyn Union, 269. forming of Consolidated and New Amsterdam, 268. Williamsburg, 269. organization of Harlem and Met- ropolitan, 267. starting of Central, Knickerbocker and Northern, 268. complaints, 162, 200, 214. consumers and gas companies, rela- tions between, 198. hints and instructions to, 207, 236. consumption, 2, 131, 135, 202. cooking by, 16, 17, 177, 178. Index 299 Gas, (Cord.} cooking stoves and ranges, 205, 219. separate riser for, 49. cost of, 4, 13, 217, 222, 266, 267, 268. for heating water, 18, 222. in London, 224. New York, 223. manufacturing, 222. danger from fire in use of, 6, 236. of water, 237. to public health in use of, 5, 6, 236, 237, 252. distillation of, from resin, 265. distribution of, 28, 238. early experiments with, in New York, 265. economy in use of, 4. engine, 20, 72, 77, 205, 219, 231, 245, 246, 247. enriched with naphtha, 267. era of, 199. escapes, 5, 214, 230, 235, 246, 247, 253, 256. examiners officially appointed, 269. exhibitions, 205, 231. explosions, 6, 245, 247. fireplace heater, 178, 205, 207. statistics concerning, 6. first New York residence illuminated by, 265. fitters, 22, 203, 205, 207. cement, use of, 27. hints and instructions to, 75. fittings (see Fittings), fixtures (see Fixtures), flames, irregular, 126, 216. flow of, through pipes, 44, 45, 46, 47, 77, 97. for cooking, 16, 17, 177, 178, 205, 273. heating purposes, 16, 275. light, heat and power purposes, advantages of, 1, 2, 16, 82, 205, 275. power purposes, 1, 2, 16, 278. street lighting, introduction of, 269. from petroleum, 244. fuel, 1, 2. furnace burning, 278. globe holders, 203. globes, 137, 201, 203. governor (see Governors), heating appliances, 204. power of, 17, 215, 224, 227, 272. stoves, 205, 275, 276. household use of, 199. illuminating, 1, 2, 82. power of natural, 82. impurities in, 244. industry, progress and development of, 263. Siemens on progress of, 271. instructions in use of, 253. Gas, (Con*.) jets, 113. keys, 144, 231, 234, 251. kinds of, 239. lamps (see Lamps), laundry irons, 42, 219, 274. leak indicator, 105. Hartenfels, 248. leaks, 5, 104, 204, 208, 209, 212, 230, 234, 246, 249, 250, 256, 260, 262. Light Company, organization of, Brooklyn, 269. East River, 268. Equitable, 268. Fulton Municipal, 269. Manhattan, 266. Mutual, 267. Nassau, 269. New York, 265. Standard, 268. light illumination, 108, 109. lighting, acetylene, 97, 188, 189. advantages, of, 199. bibliography of, 263. development of, in New York, 263. gasolene, 87, 183. improvements in, 271. injurious effects upon health and comfort, 201. in New York theatres, 226. introduction in different cities, 265. in England, 265. precautions to render safe, 212, 254. Prof. Bunte on incandescent, 273. statistics, 268, 269. logs, 19, 177, 205, 219. machines, acetylene, 185. cost of, 186. gasolene, 87. mains, 97, 135, 214, 218, 247, 258, 265, 266. manufacture, 199. manufactured, 1, 267. meters, 10, 30, 40, 148, 205, 246. (see also Meters), meter stories, 148, 164. mixed with air, explosive, 230. natural, 1, 16, 239. objections to, 5, 6. oil, 1, 180, 244. olefiant, 244. Gaseous fuel, 18, 219, 274. illuminants, 111. Gasolene machine gas, 183, 190. Gasolene, 87, 180, 183, 190, 241. cost of, 188, 189. engine, 187. fuel, 275. gas, 184, 190. lighting, 183. generators, 184. 300 Index Gasolene gas, (Cord.) specifications for, 87. gasoliers, 146, 266. gas outlets (see Outlet), pipes (see Pipes), piping (see Piping), popular fallacies about, 8, 222. pressure, 9, 10, 126, 209, (see also Pressure) . artificially increased in incan- descent lamps, 273. causes of insufficient, 215. fluctuation of, 127, 135. reduction of, 235. regulation of, 126, 128, 129, 130, 136, 203. regulators (see Governors), quality of, 8, 148, 222, 269. ranges, 16, 207, 274, (see also Range). outlets, for, 177. versus coal ranges, 275. risers, 29, 37, 39, 207. rock, 1. safeguards against danger from, 212, 254. safer than gasolene or kerosene, 275. service pipes, 23, 41, 207, 246, 253. services and water services compared, 225. frozen, 253. shades, 203. Holophane, 210, 273. shutting off, at the meter, 252. specific gravity of, 218. statistics regarding production of natural, 83. stoves, 16, 177, 205. outlets for, 177. supply, 204, 222. tables of composition of coal, natural and water, 239, 240, 241. testing, 225, 269. tips, 108, 114. tubing, 143, 250, use of, for heating laundry irons, 19, 205. natural, 82. versus electricity, 4, 273. kerosene oil, 13. vitiation of the atmosphere by, 9. warming stoves, 178. wasteful use of, 127, 203. water, 1, 241. heaters, 178, 207, 217. separate risers for, 48. wells, 82. wood, 244. works, 199. Gauges, mercury glass, 102. pressure, 27, 126. spring, 27. Generators, acetylene, 185. approved, 186. gasolene, 184. Germania Argand burners, 120. Glass globes, 204, 210, 212. shades, 137. Gleason Argand burner, 119. Beacon lamp, 120. Globe holders, 108, 139, 140, 204, 210. Globes, 108, 137, 138, 139. breakage of gas, 201. cleaning of, 204. defects of gas, 140. glass, 204, 210, 212. Holophane, 210, 273. material for, 139. Gordon Mitchell high-power gas lamp, 119. Governor burners, 117, 119, 130, 132, 133, 134, 204. Governors, 126, 130, 131, 209. automatic gas, 130, 131. float, 134. rules for use of gas, 136. station, 130. Gregory incandescent lamps, 120. mica check burner, 29. Grimston regenerative lamps, 121. H. Hall lamps, 174. Harlem Gas Company, organization of, 267. Heater, gas water, 178, 207, 219. Heat from gaseous fuel, cost of, 17. Heating and cooking fixtures, con- nections for, 252. appliances, gas, 204, 205. gas, 275. laundry irons by gas, 19, 177, 205, 274. power of gas, 227. power of water gas, 1. rooms by means of gas stoves, 19, 205. stoves, gas, 275. stoves, wall, 276. water, apparatus for, 274. water by means of gaseous fuel, 18. 205. Heat units in coal, 17. gas, 17, 227. Hefner lamps, 191. High-power burners, 120. gas lamps, 119, 120. Hints for gas consumers, 207, 221. to gas fitters, 75. Historical notes on development and progress of gas industry, 263. Holders, globe, 108, 139, 204. defects of, 140. Holophane globes, 210, 273. Index 301 Hose, metallic, 212. rubber, 212, 235. House gas pipes, 41, 42, 234. Household uses of gas, 219. House piping specifications of Consoli- dated Gas Co. of N. Y., 50. of United Gas Impr. Co. of Phila- delphia, 57. Hudson County Gas Light Company, N. J., rules of, 65. Hydraulic gasolier, water joint in, 204. Hydrocarbons, 180. Hydrogen, carburetted, 244. gas, process of making, 267. sulphuretted, 244. I. Illuminants, cost of various, 190, 191, 192. gaseous, 12, 111, 180. liquid, 111, 180. solid, 111, 180. Illuminating engineer, 110, 143. gas, 1, 2, 4, 230, 258. Illumination, artificial, 108, 142, 179, 234. by electricity, 12, 180. candle, 111/180, 264. gas, 1, 2, 12, 108, 124, 180, 265, 272. light house, 120. maximum, 200. natural gas, 82. of interiors, 108, 142, 170, 264. oil lamp, 111, 180, 181. principles of gas, 109. products of, 4, 245. street, 124. Improvements in gas lighting, 271. Impurities in gas, 244. Incandescent alcohol lamps, 183. burner, Welsbach, 123. electric lamps, 2, 180, 270. gas burners, 4, 113, 119, 123. lamp, 184, 204, 226, 271, 273. lighting, 226, 271, 273. lighting art of, 190, 192. cost of, 14. mantle burners, 3, 123, 175, 180, 209, 210, 227. Index, gas meter, 157, 202, 210. Indicator gas leak Hartenfels', 248. Joslin, 105. Muchall, 105. Industry, Dr. Siemens on gas, 271. Inspection of gas fixtures, 254. piping and fitting in cities, 270. Inspector of gas meters, 206. plumbing, report of, Washington, B.C., 232. Instructions to gas consumers, 236, 253. distribution employees, 76. fitters, 75. Insurance Companies' views concern- ing gas, 6. Interior illumination, 170, 217. Introduction of gas illumination in New York house, first, 265. Inventor of first gas meter, 148. gas lighting, 2. Inverted gas burners, 3, 113, 124, 173. incandescent gas lamps, 124, 184, 273. J. Jahn's safety regulator burner, 118. Jet burners, 113, 116. Jets, gas, 113. Joints, gas tight, 26. screw, 38, 41. telescopic, 251. Joslin gas-leak indicator, 105. Jumping gas flames, 29, 216. Junkers' gas heating stove, 275. K. Kern incandescent burner, 123. Kerosene engine for running dynamo, 187. oil, 14, 180, 275. lamps, 182. versus gas, 13. Keys, gas, 144, 204, 231, 234, 251, " all-round, " 204. Kitchen gas range, separate supply pipe for, 207. Kitchens of apartment houses, gas ranges in, 275. Knickerbocker Gas Co. started, 268. L. Lamp, acetylene, 180, 186. bracket, 146. Brilliant, 121. Brown, 121. Clamond, 123. drop, 146. electric incandescent, 2, 180, 198. extension, 176. first arc, 270. incandescent, 270. gas, 119, 198. hall, 174. Hefner, 191. high-power gas, 119, 120. incandescent alcohol, 183. gas mantle, 180. kerosene, 182. Lindsay, 123. moderator, 182. Nernst, 192. oil, 13, 181, 182, 198. 302 Index Lamp, (Con/.) osmium, 192. portable, 180, 182, 186, 210, 251. regenerative, 121, 204. safety, 6. Shaw reflector, 120. suction, 182. Sugg's "Cromartie" gas, 122. Tantalum, 192. Tungsten, 192. Welsbach, 271, 272. wicks, 181. Wolfram, 192. Lamps, advantages of, 182. ancient, 181. disadvantages of, 146. pressure, 182. requirements of oil, 182. Laundry iron heaters, 19, 177, 213, 219. Lava tips, 115. Laying of gas service pipes, 24. Leakage gas, 5, 104, 204, 209, 212, 230, 234, 246, 250, 256, 257, 260, 262. Leak indicator for gas, 105. Hartenfels' gas, 248. Leaks cost of, 208. detection of, 209, 212, 230, 234, 246, 250, 256. Length of gas piping, greatest allow- able, 36, 94, 96. Leoni burner, 116. Lewis burner, 123. Light, absorption of , by glass globes, 138. artificial, 179. flickering of, 201. loss of, 138, 215. Lighting acetylene, for towns, 186, 244. and Heating Committee, report of National Board of Fire Under- writers, 256. bibliography on gas, 263. devices, 142. electric, 187. gas, see Illumination by gas. gasolene gas, 183. of county houses, 179, 188. first New York theatre by gas, 265. interiors, 108, 142, 170, 264. isolated buildings, 241. London theatres, by gas, 265. Pall Mall, London, by gas lamps, 265. railroad cars, 3, 124. rooms (see Fixtures for various rooms, or interiors). streets, 204, 263, 264, 269. Prof. Bunte on incandescent gas, 271. recent modes of, 198. Lindsay lamps, 123. Liquid illuminants, 111. Location of gas fixtures, 212. meters, 208, 213. outlets, 22. Logs, gas, 19, 177, 205, 219. London burner, Sugg's, 179. Loss of light, 138, 215. Luminous flame, nature of. 111. Lungren regenerative lamp, 121. M. Machines for producing carburetted air-gas, 184. Mains, 97, 233, 247, 248, 249, 258. first gas, in New York, 265. fluctuations of pressure in street, 135. tightness of gas. 233, 248, 258. Management of gas, 230. Manhattan Gas Light Company in- corporated, 266. gas piping rules of, 49. Mantle burners, 3, 180. nature of the incandescent, 272. Mantles, cotton, 123. manufacture of, 227, 228, 272. self-lighting, 124. Manufactured gas, 1. Manufacture of acetylene gas from calcium, carbide, 1, 242. gas fixtures, 142. from coal, 199, 246, 267. meters, 10. Welsbach burners, 272. Matches, use of, 213, 264, 265. Maximum illumination, 200. length of gas pipes, 36, 94, 96. number of burners for different sizes of pipes, 36, 94, 96. Meter accidents due to use of prepayment, ' 253. accuracy of gas, 158. acetylene gas, 154. capacity, 76, 78. compensating, 152. complaints, 159. connections for, 155, 249. dry, 149, 150, 151. exhibition, 204. frozen gas, 253. gas, 10, 30, 40, 41, 148, 246, 252. index, 157, 202, 210. inspectors, 206. invention of the first gas, 148. location of, 38, 156, 207, 208, 213. popular fallacies about gas, 162, 202. prejudices against gas, 202. prepayment, 153. reading the, 157, 202. requirements of gas, 154. rotary gas, 152. shutting off gas at the, 252. Index 303 Meter, (Cant.) sizes of, 38, 154. station gas, 153. stories, 148, 164. tightness of gas, 249. vagaries of gas, 201. wet, 149, 151. Meteor regenerative gas lamp, 121. Metropolitan Gas Company organized, 267. Milwaukee building department rules on gas, 66. Mineral oil, 6. Mixture of air and illuminating gas, explosive, 230. Moderator oil lamps, 182. Morey incandescent gas burner. Muchall gas-leak indicator, 105. regenerative gas lamp, 121. Multiple flat-flame burner, 113, 120. Municipal building regulations on gas, 34. Murdock, Thomas, inventor of gas lighting, 2. Mutual Gas Light Company, incorpo- rated, 267. N. Naphtha, 183. Nassau Gas Light Company, incorpo- ration of, 209. National Board of Fire Underwriters, Committee on lighting and heat- ing, report of, 250. Requirements for a standard acety- lene generator, 194. Rules for piping for acetylene gas, 196. Rules for safe use of gas machines, 193. Natural gas, 1, 16, 81, 82, 239. chemical analyses of, 82. discovery of, 81. high pressure of, 82. illuminating power of, 82. piping for, 81, 83. production, statistics of, 83. composition of, 239. Nernst lamp, 192, New Amsterdam Gas Company, form- ing of, 268. New York Gas Light Company, in- corporation of, 265. Northern Gas Company started, 268. Number of burners, maximum, with given size of pipe, 36, 94, 96. O. Oil. burning of. 180. gas, 180, 244. kerosene, 13, 180, 275. lamps, 13, 81, 111, 181, 182, 198, 264. regions, petroleum, 81. Oil, (Cant.) wells at Baku, 81. Oils, mineral, vegetable and other, 6, 180, 182. Olefiant gas, 244. Ordinances on street lighting in New York, early, 263. Osmium lamp, 192. Outlets, for gas stoves and ranges, 177. gas, 22, 29, 43, 171, 173. plans for gas, 171. P. Paraffin candles, 180. Pendants, 142, 146, 251. People's Gas Light and Coke Company of Chicago, rules for size of pipe for natural gas, 86. Petroleum, crude, 83. gas, 244. oil regions, 81. Pettenkofer, Prof., on gas escapes into houses, 247. Photometric test, 272. Pipe connections, lead, 155. Pipes, arrangement of gas, in buildings, 22, 33, 42. composition, 26. copper, 26. corrosion of service, 249. fastenings for gas, 42. flow of gas through, 44, 45, 46, 47, 97. for cooking ranges, 37. for gas engines, 72. gas, 23, 41, 55. installation of gas, 5, 31. laying of service, 24. material for gas, 26. non-conducting covering for gas, 24. protected against frost, 24. screw-jointed, wrought iron gas, 23. sizes of gas, 36, 37, 42, 201. steel, 26. stoppages in, 27. Piping acetylene gas, 97, 99, 101, 186. air gas, 81. cleaning of gas, 209. dangers connected with gas, 249. defective gas, 215. gas, rules and regulations for, 203,205. inspection of gas, 230, 254, 270. natural gas, 81, 83. regulations for theatres and places of assembly, 56. requirements for gas, 36. rust in gas, 27, 209. size of gas, 36, 37, 42, 201. specifications for gas, 41, 186, 207. testing of gas, 38, 43, 102, 103, 105, 106, 107, 249, 270. 304 Index Pittsburg, fire marshal's rules for piping for natural gas, 83. Underwriters ' rules for use of natural gas, 85. Plans, gas outlet, 171. Plumbing inspector of Washington, D. C., report of, 282. Portable lamps, 186, 210, 251. Power, calorific, of gas, 272. illuminating, 272. Practical hints for gas consumers, 207. Precautions in use of gas, 212. Precision burner, Siemens, 119. Prejudices against gas, 1, 222. Prepayment meters, accidents due to use of, 253. Pressure, automatic control of, 130. causes of insufficient, 215. control of, 128, 129. evils of high gas, 127. fluctuations of, 127, 135. gas, 9, 10, 126, 209. gauges, 27, 126. increased artificially in incandescent lamps, 273. lamps, high, 182. of natural gas, 82. reducing appliances, 201. reduction of gas, 235. regulators, 108, 126, 130, 131, 136, 203, 209, 252. rules for use of, 136. Price of gas, 217, 222, 266, 267, 268. Principles of gas illumination, 109. Process of making gasoline gas, 184. hydrogen gas, Tessie de Motey, 267. Wilkinson, gas, 268. Production of carburetted air gas, 184. natural gas, statistics on, 83. Products of combustion of illuminating gas, 4, 245. Prof. Bunte on incandescent gas light- ing, 271. method of testing gas mains, 248. Junkers 'gas heating stove, 275. Progress and development of the gas industry, 263. Protection of pipes against frost, 24. service pipes against corrosion, 249. Purifying gas, 244. Q. Qualified gas fitters, employment of, 203. Quality of gas, 8, 148, 222, 269. R. Ranges, coal, 274. gas, 207, 274. Reading of meter index, 202, 210. Red lead for joints, use of, 26. Reflector lamps, 120. Reflectors, 203, 210, 212. Regenerative gas burners, 113, 120, 121, 125, 271. lamps, 121, 204. Regulating burners, automatic, 132. Regulation of gas pressure, 126, 136. Regulations for gas piping for theatres and places of assembly, 56. municipal building, 34. rules, tables and regulations of gas companies, 44, 270. Regulators, American mercury-seal, 131. dry and wet, 130. English pressure, 131, 209. Report of City Club on gas leakage, 256. Committee on lighting and heating, National Board of Underwriters, 256. Inspector of plumbing of Washing- ton, D. C., 232. Requirements of National Board of Fire Underwriters as to acetylene generators, 194. gas machines, 192. use of acetylene gas, 209. Risers, additional, for building exten- sions or alterations, 209. for gas water heater, laundry irons, ranges, etc., 42. gas, 20, 37, 39, 207. sizes of, 29, 37. stoppage of gas, 226. Rock gas, 1. Rotary gas meter, 152. Round-flame burners, 113, 118, 120. Rules for gas piping, 44, 203, 205. Boston Board of Health and Building Commissioner, 62. Gas Light Company, 61. British, 78. Bureau of Buildings, New York, 53. Chicago People's Gas Light and Coke Company, 71. Cincinnati Gas Light and Coke Com- pany, 69. Denver Consolidated Gas Company, 68. District of Columbia, 64. for acetylene gas, National Board of Fire Underwriters, 101. City of Munich, 80. gasolene gas, Detroit Heating and Lighting Company, 95. Springfield Gas Machine Company, 91. natural gas, Fire Marshal of Pitts- burg, 83. People's Gas Light and Coke Company of Chicago, 86. Index 305 Rules for Natural Gas, (Cont.J Pittsburg Board of Underwriters, 85. Rules of Hudson County Gas Light Company, 65. Milwaukee Building Department, 66. Old Manhattan Gas Company of New York, 4. Rules regarding gas fixtures, 23. use of pressure regulators, 136. tables, and regulations of gas com- panies, 44 (see also Rules for gas piping.) S. Safeguards against danger from gas, 254. Safety burners, 117. lamp, 6. matches, 213. Schilling's table for discharge of gas pipes, 47. Schiilke regenerative lamps,. 121. Screw-regulating burner, Sugg's, 132. Self-lighting devices, 124, 210, 255. Separate risers for gas cooking and heating fixtures, 42, 207. Service pipes, 23, 24, 25, 97, 246, 249, 253 (see also Pipes). Sewer gas, effects of gas leaks attributed to, 249. Shades, 212. Shaw reflector lamps, 120. Show room for gas appliances, 205. Shutting off gas at the meter, 252. Siemens, Dr., on gas industry, 271. precision burner, 119. regenerative burner, 121, 271. Silber burners, 116, 119, 129. Single- jet burner, 113. Size of pipes for gas engines, 72. meters, 76, 78, 154. piping for acetylene lighting, 100. service pipes, 25. Monnier's French table for, 80. Sizes of gas pipes, 29. Slit-union burner, 113. Specifications for gasolene gas lighting, 87. gas piping, 41, 207. for piping for acetylene gas, 186. of Consolidated Gas Company of New York, 50. Springfield Gas Machine Company, 91. United Gas Improvement Com- pany of Philadelphia, 57. Specific gravity of gas, 132, 218. Spermaceti candles, 180. Springfield gas Machine Company, specifications, 91. Standard Gas Light Company, organi- zation of, 268. Station governor, 130. meter, 153. Stations, gas testing, 225. Statistics of Board of Gas and Electric Light Commissioners of Massa- chusetts, 254. gas accidents, 235. lighting, 268, 269. Stearine candles, 180. Steatite burner tips, 115. Stop cocks, round-way, 27. Stoppage of gas risers, 226. Stoves, gas warming, 16, 19. Street illumination with Welsbach lamps, 124. lamps, Bray's high power, 120. posts, early public, in New York, 263. lamps, present and past method of lighting, 263, 266. lighting, 2, 263, 264, 266, 268. introduction of gas for, 269. mains, escape of gas from broken, 233. Suction lamps, 182. Sugg's burners, 115, 116, 119, 120, 122, 129, 132. Cromartie gas lamps, 122. improved Argand burner, 119. regenerative lamps, 121. Sulphuretted hydrogen in gas, 244. Supervision of gas fitting work by City Departments, 270. fixtures, 254. piping, official, 230, 254. Supply of gas, facts about the, 222. Swinging gas brackets, 212. T. regu- Tables from City of Munich lations, 80- of and rules for gas fittings, Chicago People's Gas Light and Coke Company, 71. capacities of gas meters, 49, 56, 78, 159. composition of coal gas, 240. natural gas, 239. water gas, 241. consumption of gas in burners, 128, 129. cost of illumination, 192. discharge of gas pipes, 45, 48, 49. gas burning hours per year, 211. pipes, Old Manhattan Gas Com- pany's, 49. piping for acetylene gas, 99, 100, 101. sizes of service pipes, 25, 80. 306 Index Table-top burner, Sugg's, 115, 116. Taj high-power gas lamps, 120. Tallow candles, 180, 181. Tantalum lamp, 192. Tapping of gas mains, 247, 249. Taps, old fashioned, all-around gas, 145. Tees, use of plugged, 29. Tessie de Motey process for making hydrogen gas, 267. Test burner, 161. flash point, 183. for impurities in gas, 244. protometric, 272. of fixtures, 144, 145, 251. gas meters, 158, 159, 161. governor burners, 134. piping by gas companies, 270. for acetylene gas, 98. Testing candlepower of gas, 225. gas pipes, 38, 43, 102, 103, 203, 208, 249. European method, 106. with air pressure, 102. stations, gas, 225. tightness of gas mains, 248. Thorp regenerative gas lamp, 121. Tightness of gas governors, 252. mains, 248. piping, 208. stoves, 249. Tips, gas, 108, 111, 115. lava, steatite, adamas and enamel, 115. Tubing, rubber gas, 143, 256. Tungsten lamp, 192. Twin flat-flame gas burner, 120. U. Underwriter rules for instalment of gasoline machines, 185. Union-jet burner, 113, 116. Upright incandescent burner, 113. Use and management of gas, 252, 273. of gas as a fuel, 273. commercial, 219. dangers from fire in, 6. day, 204. economy in, 4. Use of gaseous fuel, 20. Use of gas fixtures, 230, 255. Use of gas for cooking, 16, 17, 177, 178, 205, 273. for lighting, 205, 273. power purposes, 1, 2, 16, 278. household, 179, 219. instructions on the, 203, 253. wasteful, 127. Use of natural gas, 82, 85. oil lamps, 264. plugged tees instead of elbows, 29. Use of, (Cont.) red lead in gas pipes joints, 26. prepayment meters, accidents due to, 253. pressure regulators, 131, 203, 209. volumetric governor burners, 203. V. Vapor of condensation, 29. Variable quality of gas, 8. Variation of discharge of gas with specific gravity, 48. Ventilating gas burners, 125. regenerative gas burners, 125. Vitiation of the atmosphere by gas, 9, 127. Volumetric burners, 132, 133. use of, 203. W. Wall brackets, 108. Wall gas-heating stoves, advantages of, 276, 277. Walthamston high-power lamp, 120. Waste of gas, 203. Water gas, 1. Water gas, carburetted, 240. danger of, 237. heating power of, 1 . tables of composition of, 241. Water heaters, gas, 178, 207, 219. in gas meters, 216. Wax, 180. Wax candles, 181. Wells, gas, 82. Welsbach incandescent burner, 123. manufacture of, 272. lamps, 128, 271, 272. Wenham regenerative lamp, 121. Westphahl regenerative lamp, 121. Wet meter, 149. Wicks, candle, 181. lamp, 181. trimming of candle, 264 Williamsburg Gas Company, forming of, 269. Wiring, 187. Wire cages, 212. Wilkinson process of gas making, 268. Winsor burner, Sugg's, 129, 132. Wolffhugel, Prof., on gas escapes into houses, 247. Wolfram lamp, 192. Wood gas, 244. Wood used as fuel, 273. Y. Yotto incandescent burner, 123. Young America burner, 117, 129. OF THf UNIVERSITY WORKS BY WM. PAUL GERHARD, C E, HOUSE DRAINAGE AND SANITARY PLUMBING. Illustrated. 1 2th Edition, Science Series 63. Price 5ocents. ^ RECENT PRACTICE IN THE SANITARY DRAIN- ^ i AGE OF BUILDINGS, 2d Edition. Science Series 93. ^ s Price 50 cents. SANITARY ENGINEERING OF BUILDINGS. trated. Price $5.00. A GUIDE TO SANITARY HOUSE INSPECTION. 3d Edition. Price $1.25. THE SUPERINTENDENCE OF PIPING INSTALLA- TIONS IN BUILDINGS. (Sanitary, Hydraulic and Gas.) Price $1.00. 1 ^ THE PREVENTION OF FIRE. Chiefly with reference ij ^ to Hospitals and Asylums. 2d Edition. Price 60 cents. THEATRE FIRES AND PANICS: THEIR CAUSES AND PREVENTION. Price $1.50. | S THEATRES: THEIR SAFETY FROM FIRE AND ^ PANIC? THEIR COMFORT AND HEALTH- 'S I FULNESS. Price $1.00. | ^ ^ THE SANITATION OF PUBLIC BUILDINGS (Hos- |j j| ^> pitals, Theatres, Churches, Schools, Markets and Abattoirs). 5 5 g Price $1.50. 3^4 MODERN BATHS AND BATH HOUSES. Illus- O trated. Price $3.00 net. $ GAS LIGHTING AND GAS FITTING. 3^ Edition. ^ .| Science Series No. in. Price 50 cents. THE AMERICAN PRACTICE OF GAS PIPING AND GAS LIGHTING IN BUILDINGS. < ^ Price $3.00 net. V ^.A THE SANITATION, WATER SUPPLY AND | * ^ ^ SEWAGE DISPOSAL OF COUNTRY HOUSES. "^ ^3 1 Illustrated. Price $2.00. 5 1 1 i THE DISPOSAL OF HOUSEHOLD WASTES. Science Series No. 97. Price 50 cents. * I '3 | SANITARY ENGINEERING. Price $1.25. 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