Lot 415

John Arnold & Son, London, Invt. et Fecit, Movement No. 20/1020, 54 mm, 154 g, circa 1797
A pocket chronometer of historical interest out of Arnolds series III with Arnold's spring detent escapement, manufactured in quality II
Case: silver, hallmark London 1810, case maker's punch mark "DW" (Daniel Walker, New Shore Buildings, Clerkenwell Close). Dial: enamel. Movm.: full plate movement, chain/fusee, keywind, gold screw compensation balance according to Pennington.
This chronometer was originally built in 1797 and had most likely been fitted with John Arnold's Z balance; in1810, however, it was remodeled by John Roger Arnold. A new case was ordered from Daniel Walker, who had already created a number of pieces for J.R. Arnold. The watch was also fitted with a more modern dial, while the original set of hands was kept. Likewise, J.R. Arnold obviously decided to keep the original spring detent escapement, but he fitted the movement with a Pennington balance which was quite a novelty at the time. Here an extra heavy and high quality version of the balance was used. All in all this is a fascinating pocket chronometer that shows the gradual development of the technology used by Arnold's son John Roger Arnold in the course of the modernization process.