The object in writing the book was to furnish a clear and easily understood description of the principles, construction and operation of the locomotive engine of the present day, a subject which is not concisely or adequately treated in any one similar book. If the author has succeeded in making what he has written plain to plain people, his aim will be fully accomplished. _No. 73 Broadway_, NEW YORK. CONTENTS. PAGE Preface iii Introduction ix Part I. The Steam Engine 1 II. The forces of Air and Steam 8 III. On Work, Energy and the Mechanical Equivalent of Heat 22 IV. The Slide-Valve 30 V. The Expansion of Steam 47 VI. General Description of a Locomotive Engine 62 VII. The Locomotive Boiler 71 VIII. The Boiler Attachments 115 IX. The Throttle-Valve and Steam-Pipes 155 X. The Cylinders, Pistons, Guide-Rods and Connecting- Rods 164 XI. The Valve-Gear 181 XII. The Running-Gear 268 XIII. Adhesion and Traction 319 XIV. Internal Disturbing Forces in the Locomotive 328 XV. Miscellaneous 335 XVI. Screw Threads, Bolts and Nuts 341 XVII. Tenders 349 XVIII. Friction and Lubrication 358 XIX. Combustion 365 XX. The Resistance of Trains 406 XXI. Proportions of Locomotives 412 XXII. Different Kinds of Locomotives 427 XXIII. Continuous Train Brakes 442 XXIV. Performance and Cost of Operating Locomotives 448 XXV. Water-Tanks and Turn-Tables 451 XXVI. Inspection of Locomotives 461 XXVII. Running Locomotives 478 XXVIII. Accidents to Locomotives 509 XXIX. Accidents and Injuries to Persons 533