Accompanied by the original Thos. Russell & Son warranty dated May 23, 1901 and Kew Observatory Class A Kew Certificate dated May 16 to June 29, 1900.
Watches awarded with the renowned Kew "A" Certificate are highly precise timekeepers which were submitted to a 45 day trial at the Kew Observatory in Richmond, Surrey. The present watch obtained the Class A Certificate with the addition of 85.4 marks for superior merit, labeled especially good.
The Karussel was patented in 1892 by the Danish watchmaker Bahne Bonniksen who had immigrated to England.
Both Karussels and Tourbillons are revolving escapements with the escapement placed on a small rotating platform, a device to eliminate errors of rate in the vertical positions.
The Karussel escapement however is driven by a fourth wheel, which is not fixed but rotates within the platform. Consequently it is turning at a much slower rate than tourbillon carriages, varying from 34 to 52.5 minutes per full rotation depending upon the design. It is also more robust and easier to produce than a tourbillon.