INTRODUCTION. 9 
In the briquetting plant a number of new possible binding materials for coke briquettes 
have been investigated, and a few of these have proved sufficiently satisfactory to warrant 
further investigation as to their more extended use, at a probable cost considerably less 
than that of coal-tar pitch, which is ordinarily used for briquetting operations. A num- 
ber of lignites, representing both the extreme Northwest and Southwest, have been bri- 
quetted under high pressure without the use of binding materials, and it has been shown 
that the cost of. briquetting such materials should not exceed 50 cents per ton. Further- 
more, it has been shown that in the use of certain briquetted coals for railroad and domestic 
purposes the increase in the efficiency of the coals used in the briquetted form is more than 
sufficient to cover the cost of the briquetting operations. 
The producer-gas investigations have shown the suitability of bituminous coals, lignites, 
and peats for power purposes in the gas producer and the gas engine. While there remain 
difficulties in the way of the general introduction of "this new source of power, yet the results 
of these investigations have already contributed in an important degree toward the over- 
coming of these difficulties and are serving as a basis of plans for new power developments 
in many parts of the country. Already 14 or more different companies are reported to be 
making producers for power purposes and others are endeavoring to perfect new designs. 
It may be added that at two of our great steel plants blast-furnace gas engines have been 
introduced for power purposes,. and a dozen companies are now either manufacturing or 
working on plans for the manufacture of gas engines. 
The advances made in simplifying and handling the gas-producer equipment at the St. 
Louis plant have so increased its efficiency that the average bituminous coals recently 
tested have yielded in it 2.6 times the amount of power they have given under steam boilers 
of equivalent capacity (210 horsepower), and in several cases this difference in favor of the 
gas power has been considerably greater — as high as three to one. 
The development of the steam boiler and engine has required more than two hundred 
years, for the reason that along i:s path there was but little record of accurate data to 
serve as a basis of invention. It is confidently hoped that the information now being 
secured and assembled by the Survey will be the means of stimulating more rapid improve- 
ments and higher efficiencies in the use of fuels along several lines, and particularly of dem- 
onstrating the great practical possibilities of power developed with the gas producer and 
engine. 
In connection with the large beds of lignite found in many of the Western States, the 
present investigations have been and will continue to be of much value in showing how 
these lignites may be used to advantage for power purposes, either in their natural condi- 
tion, in gas producers and gas engines, or briquetted and then used under ordinary boilers, 
in gas producers, or in ordinary domestic stoves and furnaces. 
These investigations, in addition to demonstrating how many of the so-called noncoking 
coals of the United States may be coked by exercising increased care either in the con- 
struction or -in the operation of the ovens, have also shown how the quality of certain of 
these cokes may be improved by adding pitch or other hydrocarbons to the coal before 
being charged into the oven. 
A not unimportant result of this work is educational, through (1) the awakening of the 
coal producers of the country to a more careful study of their coals and of possible methods 
of improvement in quality by washing, etc., and (2) the recognition by manufacturers and 
other coal consumers of the need of using their fuels more efficiently, and of purchasing 
them on a basis which indicates their true heating value, rather than on some general and 
indefinite trade name or classification, or at the "lowest price." 
During the remainder of the present fiscal year (to June 30, 1906) the work of the fuel- 
testing plant will be largely confined to comparative tests of the fuel efficiencies of coals 
and lignites collected from different coal fields. But if provision is made for continuing 
the investigations beyond this period, there are a number of important fuel problems that 
await investigation and that should be investigated by the Government, not only because 
of their importance but because of the further fact that the solution of these problems has 
