19th century, signed on its engraved steel dial; the instrument's platform is affixed with two levels, two sighting posts and a socket mount. Included is a lidded wooden case, its interior with remnants of green felt and a fragmentary makers' label for Amsler & Wirz, Chestnut Street, Philadelphia.

Wear from normal use; original brass surfaces; the case with stains and a one inch split to the top.