Watch Repair Glossary

Horology, or the study of time, has evolved with its own terminology over the millennia.

For example, the Tourbillon (French for “whirlwind”) is designed to increase a watch’s accuracy. Patented in 1801 by French-Swiss watchmaker Abraham-Louis Breguet, it’s essentially a rotating carriage device making one rotation per minute. When the watch’s balance, pallet and escape wheel are mounted in the tourbillon, the device averages any errors in the vertical positions.

Your Watch Service or Repair

For today’s customers having a watch serviced or expertly repaired, please ask us if about any terms you may not understand. We’ll gladly explain.

Here’s a small sampling of common terms you may hear in a discussion with one of our Timekeepers or Watchmakers.



The greatest angular displacement a balance moves – measured from the zero or rest Position to position of maximum displacement, expressed in degrees.

Abraham Louis, 1747 – 1823 Horological genius / inventor. The name given to the type of balance spring which has its outer coil raised above the body of the spring & curved inwards.

A watch with hands that display hours, minutes and seconds, together with an additional mechanism for measuring continuous or interrupted periods of time and set to zero independently of the watch movement.

A watch that has obtained a certificate from an official neutral testing center such as “COSC” (Controle Officiel Swiss des Chronometres) or “SOCC” (Swiss office for chronometric controls) after having passed strict precision tests for accuracy. These tests are performed in a laboratory over a minimum 15-day period. They test the movement alone, using successive daily rate figures at different temperatures and with the movement in different positions.

Poising a balance by observing its errors on a timing machine while the watch is running at a reduced amplitude and at various positions.

French term for a movement blank, i.e. an incomplete watch movement which is sold as a set of loose parts, comprising the main plate, the bridges, the train, the winding and setting mechanism and the regulator. The timing system, the escapement and the mainspring, however, are NOT parts of the “ébauche”.

A nickel, steel alloy containing other additions such as chromium, manganese, titanium, tungsten or beryllium, which has a very low thermoelastic coefficient over the range of temperatures commonly encountered by a watch. Used in modern balances and springs, derived from the words “elasticity” and “invariable”.

Provides the balance with fresh additions of energy at regular intervals, and simultaneously prevents the movement from racing ahead and expending all its energy in a few mad seconds.

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Peter Perry

Peter is an independent journalist and an accomplished author. He possesses over 45 years of management and business development experience. Peter is a native of Upstate New York and was the founder and CEO of a leading healthcare technology company that served state and federal government agencies and several notable Fortune 1000 companies across the US. Prior to founding his own company, he was employed by the IBM Company in sales, marketing, and support positions. He has extensive management and entrepreneurial experience in a variety of business sectors. He has participated in special management programs such as the Entrepreneurial Program at The Wharton School of Business and the IBM President’s class at Babson College. He has authored three books on computer technology and writes an independent news column and has consulted with and provided management assistance to organizations large and small in a variety of industries. He recently completed an authoritative Novel “The Union” which is scheduled for release in February 2022 by Archway Publishing (Simon and Shuster). It is an in-depth look at the corruption within organized labor and their criminal relationships with the mafia and politicians. Peter can be reached at… Your comments are invited.


William Thompson

Life and Times

With an a Master of Fine Arts diploma in one hand and an Anthropology PhD in the other, William Thompson discovered a way to parlay his passion for mountaineering into a fascinating career as a photojournalist – using the camera lens as his ultimate “paintbrush.”

Thompson worked for 12 years with National Geographic, having created the first and only complete aerial coverage of Mt. Everest for the magazine. Other exotic assignments involved traveling via yak train through the Bhutanese Himalaya, living with pygmies in deep of Africa, and photographing the Asian elephant on its tragic path toward extinction.

His commercial image work includes major campaigns for Wells Fargo, Leo Burnett, Starbucks, Marlboro, Boeing, United Airlines, Intel, and Holland America.

Today, Thompson lives in a 90-year old log home near the waters of Puget Sound – and still finds adventure in climbing. Fee free to reach out to William via the following points of contact:

William Thompson Photograph/Film
15566 Sandy Hook Rd. NE
Poulsbo, WA