S05-010. English, 3rd quarter 19th century, unsigned, but with trade label of "J. H. Steward, OPTICIAN, LONDON" inside the lid. Bright lacquered brass readout circle, 6 3/8" diameter, with inlet 360 degree silvered scale, graduated to 1/2 degree and marked every 10 degrees. The 3 black oxidized brass arms are 15" in radius, with screw-on extensions adding 11 3/4" to them. The 2 outer arms are fitted with silvered vernier scales, providing arc minute readout, and brass clamp and tangent screws for fine adjustment. The pointer is in very fine overall condition with virtually all of its original lacquer finish. The original hand dovetailed fitted mahogany case, 19 3/8" wide x 8 1/2" deep x 2 1/4" high, is also in fine overall condition, with its original finish and hardware. A station pointer is used for sounding operations and coastal navigation. When the 2 moveable arms are set for the angles between 3 known landmarks, the pointer is moved around the chart until the landmarks fall on the 3 arms. The center of the pointer then defines the ship's location.
