A month duration mahogany astronomical longcase regulator by George Graham, London, circa 1725, No. 621, known as 'Graham No.1'

Record summary

Held and catalogued by Royal Museums Greenwich (object number ZBA2211), this is a longcase regulator by George Graham, made in London, England, dated c. 1725. The Atlas places it in the Early Modern Horology period (1600 – 1750) of its Clocks collection. Recorded dimensions: Overall: 1800 x 420 x 270 mm. The record is illustrated with 6 photographs.

Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.

Catalogue description

Atlas type guide

Longcase (tall-case or grandfather) clocks

The longcase clock was born from two seventeenth-century innovations: Christiaan Huygens's pendulum (1656–57) and the anchor escapement (c. 1670). A long seconds pendulum, nearly a metre long, swings with a small arc, and enclosing it together with the driving weights in a tall wooden case protected the mechanism and created a new piece of furniture. London makers such as Ahasuerus Fromanteel, Thomas Tompion and Joseph Knibb set the pattern.

By the eighteenth century longcase clocks were made throughout Britain, the Netherlands, Scandinavia (the Swedish Mora clock), France (the Comtoise from the Franche-Comté), Germany and colonial America. Eight-day movements with two weights became standard in better clocks; thirty-hour clocks with one weight and a rope or chain were cheaper alternatives.

General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.

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