Hand Book of Calculations for Engineers and Firemen was written by mechanical engineer Nehemiah Hawkins as a practical mathematical reference for people operating and maintaining steam machinery. This copy was likely published around 1901–1902 by Theodore Audel & Co.

The handbook covers calculations related to steam engines, boilers, pumps, shafting, safety valves, piping, horsepower, steam pressure, and mechanical power. It also introduces arithmetic, algebra, geometry, measurement, and other mathematical principles needed in engineering work.

Rather than relying heavily on advanced mathematical notation, Hawkins presented calculations through plain arithmetic, reference tables, diagrams, worked examples, and practical rules. This made the book accessible to engineers and firemen who learned their trades through apprenticeships and hands-on experience.

Portable reference books like this were important tools in boiler rooms and power plants. They allowed operators to calculate equipment capacity, steam pressure, pipe dimensions, material weights, horsepower, and other values needed to operate machinery efficiently and safely.