Clocks Magazine
published my article on George Sanderson’s ingenious watch key in its March
2017 issue.
The key is not only fascinating in its functionality, but
looks good too:
Courtesy of the
Trustees of the British Museum
It’s
a small device, just 36mm in length. The
concept is elegant and simple: the motion induced in the key by the act of
using it to wind a watch daily was also used to drive an internal train of
toothed wheels such that information values displayed are updated by relevant
24 hours units. The implementation of
the concept is a little more complex!
The patent is number 777, dated 5th October 1762, referring to:
New-invented machine,
called a Lunar and Calendar Watch Key, constructed upon mechanical principles,
and adapted to every watch hitherto made, and acts thereon no otherwise than a
common key; but, by means of a screw and wheels of a curious construction, is
capable of shewing (sic), in the most accurate manner, the age of the Moon, the
Day of the month, the revolution of the tides and several other motions; which
said machine is also constructed to answer all the above-mentioned purposes
independant (sic) of any watch whatsoever, and that in the most plain and easy
manner, and will be of great benefit to His Majestie’s subjects, and more
especially to those using the sea.
My article also
reviews later (19 century) implementations of the same idea, most notably by Etienne
Tavernier. Some very attractive examples
emerged from his Paris workshop, including this, from circa 1810:
Courtesy of Sotheby’s
Etienne
Tavernier was born in 1756 and died in 1839.
His brothers – Louis and Pierre Benjamin – both worked in the watch
trade, as had his father, Jean Pierre.
Pierre Benjamin was famous as a casemaker supplier to Abraham-Louis Breguet,
with whom Etienne also collaborated.
