Reflecting circle made by Edward Troughton, London, about 1820. Anodized brass frame and index arm, polished limb, a wooden handle. Signed on the index arm: Troughton | London. Marked on the index arm: [broad anchor] | FO | 11. Inlaid silver scale from 0° to 360° every 20'. Four silver verniers to 20", zeros at the right. Brass finder arc with two scales from 0° to 140°. A detached U-shaped bracket holds a second handle with a brass-lined hole for placing the instrument on a stand; a third handle is screwed on the front of the frame. The telescope arm is rigidly fixed to the frame, the limb and the index arm can be rotated. Three index shades (two red, one green); no index shades. Index-glass adjustment by screw; adjustment of the horizon glass by capstan screw. Magnifier on a 220 mm swivelling arm, serving all verniers; the magnifier is fitted in a brass disc painted white on the back for reflection. Threaded telescope bracket in two parts, fitted for correcting collimation error; perpendicular adjustment by rising-piece and a milled collar. Fixed telescope (213 mm) inverted image, two parallel cross-wires; extra draw tube (83 mm), inverted image, two parallel cross-wires; extra draw tube (stuck in the box), two parallel cross-wires. A bubble level is fixed to the frame, for using the instrument on land, on a stand. Four shaded eyepieces (green, orange and two red); adjusting pin. FO 11 probably refers to the Hydrographic Office numbering adopted in February 1828. Square fitted mahogany box, containing a trade label for John Dennett Potter, 31 Poultry, London, and painted on the outside: Admiralty. HO [broad anchor] 14, and engraved on the lid: [broad anchor] | F 0 | 14.