Audels Engineers and Mechanics Guide 5 is part of Frank D. Graham’s eight-volume reference series on modern engineering practice. First published in 1921, the collection was prepared for engineers, mechanics, electricians, students, and industrial workers.

Volume 5 focuses on steam, fuel economy, and boiler construction. Its illustrated question-and-answer lessons explain how steam is generated and used, how boilers are designed, and how fuel and combustion affect efficiency.

The volume also examines steam-engine components and operating systems. Diagrams like the one beside the title page allowed readers to compare different mechanical arrangements and understand how valves and other components controlled the movement of steam through an engine.

This volume reflects the growing importance of fuel efficiency during the early 20th century, when engineers worked to produce more power while reducing fuel use and operating costs. It is preserved as part of the museum’s complete eight-volume Audels collection.