Brass instrument, with horizontal dial with a 5 3/8" needle and scale from 0 to 110. The needle is mounted on a vertical spindle about 5" long. The spindle is mounted on bearings at top and bottom, the latter being a needle in the center of a mica disc. A fine spiral spring extends over 4" of the spindle, and is attached to it at the bottom and to the frame at the top. The spindle and spring are covered by a brass housing which can be pulled off. Instrument has ill-fitting top which may not be original. Top is inscribed with "S. Homer May 27 1863" and "Samuel Homer Aug 27 1863."