Clocks and Timekeeping:
* Clocks and Watches: An Illustrated History (1974): His most famous work, a comprehensive overview of the development of timekeeping devices from ancient times to the 20th century.
* The History of the Clock (1975): A shorter, more condensed version of the previous book.
* Clocks & Watchmaking (1982): A guide to the mechanics and construction of clocks and watches.
Other Technical and Historical Works:
* The Invention of the Electric Telegraph (1970): A detailed account of the history of the telegraph.
* The Evolution of the Automobile (1979): Tracing the development of the car from its earliest origins.
* The History of the Motor Car (1983): Another book exploring the history of the automobile.
* The History of the Helicopter (1985): A comprehensive look at the history and technology of helicopters.
* The History of the Computer (1991): A detailed examination of the origins and development of computers.
* The History of the Aeroplane (1994): A detailed study of the development of airplanes.
Other Books:
* The Military Guide to the British Isles (1954): A guide to military history and sites in Britain.
* The History of the Ordnance Survey (1970): A comprehensive history of the British mapping agency.
Ord-Hume's writing style was characterized by meticulous research and clear explanations, making his books valuable resources for both historians and enthusiasts of technology.