Unusual Thirty-Hour Marine Chronometer, No. 29

George Margetts was working on a marine timekeeper at the same time as John Harrison. Although he relied on Harrison’s research, he exhibited great individuality. This example has a regulator-style dial comprised of three dials. The very large fusee with Harrison’s maintaining power and an Earnshaw-style spring detent escapement are standard chronometer features. But the solid foot detent and the twin helical balance springs mounted one within the other are highly unusual, exhibiting Margetts’ ingenuity.

George Margetts was an accomplished astronomer as well as horologist. He was equally active in both fields and did not clearly favor either the timekeeping or lunar distance method for determining longitude. His work suggests he was heavily influenced by French horology. He created timepieces with solar and sidereal time, as well as complicated watches that showed the tides at various ports, the phases and position of the moon, the location and declination of the sun, and the visible stars. He was even awarded £100 by the Board of Longitude for finding and correcting a number of errors in the astronomical tables which they had published. Although his work at times shows crudeness, he was a great innovator and should be credited for his efforts in improving the chronometer.