Brian Bell's encyclopaedic book traces the evolution of the farm tractor from the days of starting handle and pan seat to current 4-wheel drive machines with air-conditioned cabs and computer management systems. Although he deals in particular with developments of the classic period from the 1950s to the 1990s, he also discusses developments of the early twenty-first century.

The book is arranged alphabetically by manufacturer from Allis-Chalmers to Zetor, one hundred marques in total. These are all machines to be found on British farms irrespective of their country of manufacture. Brian runs concisely through the histories of the companies and their major models, illustrated with a wealth of photographs and extracts from sales literature. Also included are special features on items such as hydraulic systems and cold-starting aids, as well as a glossary and full index.