An early 19th Century English rack lever with 15 second subsidiary and Liverpool window jewelling in silver pair cases. Full plate gilt keywind fusee movement with plain gilt dust cover. Chased and engraved cock inscribed “Patent” on the foot, diamond endstone. Polished steel Bosley regulator with bi-metallic temperature compensation curb. Plain polished steel balance with blue steel spiral hairspring. Large Liverpool window screwed in jewelling. Rack lever escapement with thirty tooth escape wheel, adjustable slides to the lever. Off white enamel dial, subsidiary seconds marked to fifteen seconds, the hand mounted on the escape wheel arbor rotating four times every minute. Roman numerals, blue steel seconds hand, gilt hands. Well fitted in contemporary silver pair cases, lateral steel stop lever.