A practical manual for locomotive engineers and mechanics that explains selection and training of engine crews, systematic inspection and preparation of locomotives, boiler and running-gear care, firing techniques, and methods for economical, efficient operation on various services including fast freights and steep grades. It presents elementary mechanical principles, valve-motion and repair procedures, diagnostic guidance for common faults, and hands-on maintenance practices, illustrated with diagrams. Emphasis is on step-by-step procedures, fuel economy, safety, and the engineer's responsibilities, aimed at improving skill, reducing wear and operating expense, and providing clear instruction for both engine-room personnel and shop mechanics.