The general rule : a guide to customary weights and measures

An essential collection of articles, tables and notes, to define and explain the modern uses and relationships - as well as the global origins, evolution and culture - of the units composing what became known as the Imperial System, but has since in practice become the universal Anglo-American system of customary measures.

For use in the home, in schools, in government and public bodies, by trade, industry, the media and in countries overseas.

For quick reference, occasional consultation, continual study or simply reading for pleasure.