20 BULLETIN 102, VOL. 1, UNITED STATES NATIONAL MUSEUM. 



briquetting of low-grade coals, and to a limited degree around the 

 manufacture of domestic "coke." 



Producer gas is the result of the complete gasification of coal 

 under the action of a mixture of air and steam.^ Both high-grade 

 and low-grade coals may be employed in its manufacture and the 

 gas may be produced with or without the recovery of the by-products, 

 ammonia, benzol, and tar. Most of the foreign by-products producer- 

 plants, however, at least before the war, made adequate recovery of 

 the ammonia only. The producer principle is not only successfully 

 applied to central plants manufacturing gas for transmission as such 

 or for the generation of electricity; but it is also employed in smaller 

 and more mobile installations, known as suction plants, in which the 

 ^as-producer and gas-engine are a single unit. The suction plant, 

 therefore, adapts raw coal to immediate use in the internal combus- 

 tion engine, combining the efficiency of the latter with the mobility 

 of the steam engine. Thus producer-gas is suitable not only for large 

 service stations, but also for smaU industrial plants and even for 

 marine engines and locomotives. The manufacture of producer-gas 

 from coke, peat, lignite, and high-ash mine refuse has become so 

 thoroughly estabUshed on the continent as to be a commonplace 

 procedure. The widespread use abroad of the producer gas principle 

 has brought into competition with high-grade coals used as such the 

 low-grade coals and coal-like substances needed to supplement a 

 limited fuel supply. 



The briquetting of low-grade lignitic coals and coal slack has been 

 successfully practiced in Germany and other European countries for 

 over 30 years, thus, together with the results attained by producer 

 gas, bringing into service types of coal largely unused in the United 

 States. A number of special forms of fuel coke, approximating 

 artificial anthracite, have met with some measure of success, especially 

 in England, where they are sold under the trade names of coalite, 

 charco, coalexld, and others. 



As a war measure, the belUgerent countries of Europe were 

 forced to take radical steps in order to insure an advantageous use 

 of their coal resources. The French and Italian Governments 

 assumed complete control of distribution. In May, 1917, the 

 Russian provisional Government took over the coal mines of that 

 country for the purpose of controlling distribution and prices. Early 

 in the war, Germany centralized the entire coal industry under 

 Government control and a recent report states that the use of 

 raw coal has been forbidden. In England, the coal mines are 

 under full Government authority and in addition a board of fuel 

 research has been established which is recognizing both the economic 



» It is strictly speaking modified or semi water-gas, lower in calorific value than water-gas proper which 

 is made by gasifying coke or anthracite under the action of steam. 



