16 BULLETIIsr 102, VOL. 1, UNITED STATES NATIONAL MUSEUM. 



Three types of gas made from coal are in general use — coal gas, 

 carbureted water-gas, and mixed gas. Coal gas is distilled from 

 bituminous coal by heating the latter in retorts. Carbureted water- 

 gas is produced as a result of the action of steam upon coke or 

 anthracite, the nonilluminating water-gas thus produced being 

 then "carbureted," or enriched, by the addition of a gas of high 

 thermal and illuminating power made from oil. Mixed gas is a 

 mixture of coal-gas and carbureted water-gas and is suppHed in 

 many cities in the United States, the coke from the coal-gas pro- 

 duction furnishing the basis of the water-gas manufacture.^ 



The gas companies are by nature and in fact pubhc utihties. They 

 manufacture a necessity which does not lend itseK to competition. 

 They are private enterprises under municipal control, which is 

 largely directed, however, to price restrictions, and is not con- 

 structive in the way of compelling advances in technical procedure. 

 With some exceptions, the average municipal gas plant is a small 

 and antiquated organization, both in practice and in vision, far 

 behind present possibilities of manufacture and apphcation.^ In 

 some cities in the United States, the gas companies are in the nature 

 of large public-service corporations, which have made considerable 

 advance in gas production, but nowhere is there full by-product 

 recovery and the price of city gas is uniformly high. 



Although the municipal gas plant now meets rather inadequately 

 only a small share of the fuel needs of the community which it serves, 

 it represents an established activity which can be converted into an 

 organization that will supply all the fuel, whether gaseous or solid, 

 that the community requires. The transformation may retain the 

 gas mains and much of the other equipment of the present type of 

 plant, but in the place of the present procedure with relative neglect 

 of by-product recovery will be substituted a by-product system of 

 coal distillation, producing artificial anthracite, gas, ammonia, 

 benzol, and tar. This will mean in each city a centrahzed purchase 

 and consumption of raw coal, and a centralized distribution of prod- 

 ucts. The output wiU be Hmited at first, at least, by the demand for 

 solid fuel. A production of ample sohd fuel will give an excess of gas 

 over that now produced, which will call for an expansion in the use 

 of gas, both in the home and in industry. Such expansion wiU 

 come as a result of cheaper gas, incidental to the proposed plan of 



J In many cities the gas plant is hampered by the imposition of a standard based on candle-power. This 

 is a survival of the flat-flame use of gas, and now that the incandescent mantle makes heat in the flame and 

 not artificial enrichment in the gas the true object to be sought, a calorifice standard should supersede alto- 

 gether an illuminating one. 



* In Great Britain the gas industry is far in advance of that ru the United States; allusion has already 

 been made to the important r61e it has been able to play in that coimtry by supplying toluol for explosive 

 manufacture. It should be emphasized that the gas industry in the United States has been impeded by 

 restrictions imposed by economic conditions and by the type of public control affecting its affairs and in 

 consequence is by no means wholly responsible for such delinquencies as exist. 



