Waltham 1857 P.S. Bartlett Model

This American Waltham is an older design. It's an 1857 model, 18 size, P. S. Bartlett. It is key-wind and key-set.

Note the older English style tangential escapement. I always point these out as it is typical of early American made watches, modeled after English designs. England dominated the watch industry prior to the rise of the American factories which their superior automation.

There are the usual secondary serial number stamps on all the major components. 

Here is the ratchet on the dial side, under the mainspring arbor. The ratchet spring is some serious business on this watch.

The ratchet is covered by a clamp.