HOROMETRY

Definition

Horometry is the art and science of measuring and dividing time. The term comes from the Greek hôra (hour, time) and metron (measure), and designates the broadest discipline encompassing all the methods and instruments used to grasp the passage of time.

An encompassing discipline

Horometry precedes and encompasses more specialized disciplines: it covers both the theoretical division of time (hours, minutes, seconds, calendars) and its practical measurement by instruments, whether sundials, water clocks, hourglasses, or mechanical clocks. It thus forms the common conceptual foundation for horology, the art of making measuring instruments for time, and for chronometry, the science of their evaluation and certification.

Historical roots

The term appeared in French in the 19th century to designate this general science of time measurement, at a period when mechanical horology was becoming structured as a scholarly discipline, relying on astronomy and physics to establish ever more precise time references.

Good to know

In common usage, the term horometry has given way to the more specific words horology and chronometry. It remains, however, used in a scholarly or historical sense to designate the general science of time measurement, of which horology is the instrumental and craft expression.