Front, Dial, Wind and Set Lever, Back, Case Mark, Cuvette, Cuvette Mark, Movement, Hairspring Close-up, Angle view of movement.

This is a very early example of a Walsh chronometer with a duo-in-uno hairspring. The hairspring has a helical section with a short coil to attach to the stud with a flat hairspring section at the "bottom" where it attaches to the balance arbor collet.

This watch is also a keyless fuzee with an interesting keyless mechanism. The small lever at the 11:00 position can be pushed toward the 12:00 position for setting the hands. When it is returned to the rest position, the watch can be wound. When the bezel is closed, the lever is pressed inward and the crown is disconnected from the winding.

The disconnect mechanism is similar to that patented by Kullberg. On Kullberg's version the lever is pushed in to set the watch and is disconnected in the middle position. When unrestrained, it goes to the full out position for winding.

The case is hallmarked for Chester 1864. This may be an appropriate date, but the case clearly was made for a movement that swings up with a dial plate hinge. It could not work with a keyless watch and was almost certainly originally a keywind. It is possible that the watch was upgraded to have keyless work since it has functional winding and setting squares. It also has a very low serial number.  However, it is unlikely that Walsh would have used a provincial case maker. It is possible that Sam Hammond ordered the watch with the case from a maker of his choosing. He was, after all, a major customer of Walsh.

I have not disassembled the watch to look for signs that the keyless work was added after the original manufacture of the watch. If it was, the case is more likely to be  original.