It was the highlight of the second part of a private collection that the auctioneers have titled ‘Celebration of the English Watch: John Harrison’s Enduring Discovery’.
The sum was close to three times the estimate of £130,000-150,000.
The movement, signed John Arnold, London, Inv. et Fecit London, includes the ‘double S’ balance introduced by Arnold in 1780, considered amongst the most elegant compensated balances ever made. The shaped ‘S’ sections are bi-metallic and designed to overcome the changing elasticity of the balance spring and expansion of the balance’s rim in different atmospheric conditions.
Numbered 23/78, this is the only watch of its kind that survives complete with its original 7cm silver consular case (hallmarked for John Terrill Pain, London 1781), white enamel dial and the gilded full plate movement wholly intact. Two other similar Arnold watches from this period are known (number 1/36 and 2/43) carrying a similar ‘double T’ balance. By 1782 Arnold had upgraded his escapements with the use of an overcoil balance spring.
With this improvement his watches kept time to within one or two seconds per day – the first accurate pocket timekeepers.
Offered at the Sotheby’s auction on July 7, this particular watch, like many in the catalogue, is illustrated in The English Watch, 1585-1970 by Terrence Camerer Cuss who acquired it from a private collection in 1947.
The buyer’s premium was 25/20/12%.