A rare and unusual early 19th Century English chronometer by Arnold in a silver open face case and mahogany deck box. Unusual full plate gilt keywind fusee movement with the balance set into the plate. Harrison's maintaining power. Blue steel ratchet click and spring for the barrel setup. Flat plain cock with diamond endstone, compensation balance employing quarter timing nuts, freesprung blue steel helical hairspring, adjustable brass stud. Arnold spring detent escapement carried on a sub plate, short detent, jewelled impulse. Signed and numbered white enamel dial with subsidiary seconds, Roman numerals, blue steel hands, the minute hand secured to the round cannon by a screw. Substantial plain silver open face case, maker's mark “TH” in a rectangle and number corresponding to that on the movement. Small slot cut in the rim to allow the balance to be removed while still in the case. Fitted in a three tier mahogany deck box with brass furniture.
Very unusual layout for a pocket chronometer, perhaps unique in Arnold's work. See 100 years of Precision Timekeepers by Hans Staeger, page 243, for this watch where it is described as being in “nearly new condition”.