Technical paper issued by the Bureau of Mines over studies of low-grade fuel use in Europe. The results of the studies are presented and discussed. This paper includes tables, and illustrations.

Report discussing an international conference on mine-experiment stations assembling in Pittsburgh, Pennsylvania. The United States sent invitations to countries that had mine-experiment stations, Great Britain and Canada were the only countries, that did not accept invitation.

From Introduction: "For purpose of procuring data that could be using in estimating the value of the briquetting process as applied to American fuels, the United States Geological Survey, in cooperation with other interests, began in 1904, at the Louisiana Purchase Exposition, certain experiments involving the production and use of bituminous-coal briquets."

From Introduction: "Because the limited time available would not permit a careful inspection, much less a detailed study of all the plants visited, the writer has not aimed in this bulletin to present a comprehensive review of producer-gas power-plant development in Europe, or even to give such conclusions as might be drawn from what he saw, but has simply described some interesting features of European practice that attract the attention of even a casual observer."