The dial carries the large hour circle with two successive cycles of Roman numerals from I to XII. On the right is the signature "Nairne & Blunt London." The hands are missing. The brass movement is driven by a powerful spring inside a barrel with a thick chain and stocky fusee. There is a verge escapement; the contrate wheel axle is at a slant. The six-arm brass balance oscillates on the vertical plane. Side-winding is by means of an endless screw that engages with a diagonal-toothed wheel at the narrow end of the fusee; at the larger end is the first wheel of the train, which engages with the wheel that completes one revolution in 24 hours. Three crown wheels provide the minutes and seconds display. The verge escapement was almost certainly chosen because it offers the advantage of re-starting automatically when released.