From Introduction Scope and Purpose of Inquiry: "The Bureau of Mines, to which the testing and analyzing of fuels as carried on by the United States Geographical Survey has been transferred, is continuing producer-gas investigations at the testing station at Pittsburgh, Pa. Results of the gas-producer tests made at the coal-testing plant erected at St.Louis, Mo., and of a study of some of the problems that came up in the tests have been published by Geological Survey. Results of the tests made at Norfolk, Va., and Pittsburgh, Pa. and of further studies of particular problems, will be published by the Bureau of Mines."

From Introduction: "In the course of this study many incidental problems of prime importance have demanded consideration. Among them is the determination, under practically constant conditions, of the duration of gas-producer tests necessary to reduce the possible error to minimum. A discussion of this proper length of test period forms the part of this bulletin."

From Scope of Report: "The purpose of this report is, therefore, to present in convenient form all the more important data accumulated in the course of the tests described, in order that the results may be readily accessible both to the Government officials having charge of the design, purchase, or care of power plants and to all persons interested in the development of the internal-combustion engine and the gas producer as means for utilizing the energy of fuels."