engines; methods of working; portable oil engines, etc., etc. Index and tables. XIII. + 196 pages, 7-1/2 ◊ 5-1/2, 79 illustrations, cloth, $2.00 * * * * * PRACTICAL HANDBOOK ON GAS ENGINES. _With Instructions for Care and Working of the Same._ By G. LIECKFELD, C.E. TRANSLATED WITH PERMISSION OF THE AUTHOR BY Geo. Richmond, M.E. TO WHICH HAS BEEN ADDED FULL DIRECTIONS FOR THE RUNNING OF OIL ENGINES. CONTENTS. Choosing and installing a gas engine. The construction of good gas engines. Examination as to workmanship. As to running. As to economy. Reliability and durability of gas engines. Cost of installing a gas engine. Proper erection of a gas engine. Construction of the foundation. Arrangement for gas pipes. Rubber bag. Locking devices. Exhaust pipes. Air pipes. Setting up gas engines. Brakes and their use in ascertaining the power of gas engines. Theory of the brake. The Brauer band brake. Arrangement of a brake test. Explanation of the expressions "Brake Power" and "Indicated Power." Comparisons of the results of the brake test and the indicated test. Quantity of work consumed by external friction of the engine. Distribution of heat in a gas engine. Attendance on gas engines. General remarks. Gas engine oil. Cylinder lubricators. Rules as to starting and stopping a gas engine. The cleaning of a gas engine. General observations and specific examination for defects. Different kinds of defectives. The engine refuses to work. Non-starting of the engine. Too much pressure on the gas. Water in the exhaust pot. Difficulty in starting the engine. Clogged slide valve. Leaks in gas pipes. Unexpected stopping of engine. Irregular running. Loss of power. Weak gas mixtures. Late ignition. Cracks in air inlet. Back firing. Knocking and pounding inside of engine. Dangers and precautionary measure in handling gas engines. Examination of gas pipes. Precautions when:-Opening gas valves. Removing piston from cylinder. Examining with light openings of gas engines. Dangers in starting. Dangers in cleaning. Safeguards for fly-wheels. Danger of putting on belts. =Oil Engines.= Gas engines with producer gas. Gasoline and oil engines. The "Hornsby-Akroyd" oil engine. Failure to start. Examination of engine in detail. Vaporizer valve box. Full detailed directions for the management of Oil Engines. Concluding remarks. 120 pages, illustrated, 12mo. cloth. $1.00 * * * * * THE CHEMISTRY OF FIRE AND FIRE PREVENTION.