This is a picture of the famous H1, Harrisons first marine chronometer, to be found in full working consition at the National Maritime Museum, Greenwich, London. It has twin oscillating balance arms on roller bearings, with grasshopper escapement, and is a sheer joy to see working. It wasa ctually taken on a voyage to Lisbon, and on the return journey helped to fix the position of the Royal naval vessel. This clock has a very famous history, and Harrison built four further sea clocks during his lifetime, ending with his sea watch, for which he eventually won the Longitude Prize near the end of his life.
Harrison's clock provided the inspiration to try and build something similar in Meccano, and here is the Meccano version.
This clock was shown at Skegness in 1987 and won the Issigonis Sheild. It was fully written up as a ModelPlan in the NMMG magazine for July 1988. The clock has been through a number of incarnations since then, and the escapement and power supply have been very much improved. Sinclair Harding, the famous clockmakers of Cheltenham sold a commercial version of the clock, and the present Meccano sea clock is now also called the Sinclair Harding.