Artificial horizon with boxwood bottle of mercury, 1850-1900 Artificial horizon with boxwood bottle of mercury
Artificial horizon (incomplete) by John Frederick Newman (I. Newman) Artificial horizon (incomplete) by John Frederick Newman (I. Newman)
Two artificial horizons L150 and L159, by The Sperry Gyroscope Corporation, United States of America, 1929-1949 Two aircraft Artificial Horizons L150 and L159: 1929-1949 1929-1949
Brass sextant with lacquered frame and limb, wooden handle and fitted with artificial horizon invented by Alexander Bridport Becher in 1834, and made by William Cary, London, England, 1835-45. Consists of inlaid polished silver 126° scale (-5° to 150°) with 20’ divisions and silver vernier (20”), three index-filter shades (red & 2 green), three horizon filters (red & green), scale magnifier on 55mm swivelling arm. Fitted with threaded telescope bracket for sighting telescopes (151mm – inverted image). The horizon consists of a 93-mm-long anodized brass tube with a bracket for attaching it to the sextant. The tube contains a pendulum that is lowered into a conical attachment (missing) filled with almond oil to dampen the pendulum's movement. A separate oil lamp (missing) can be fixed to the bracket for illumination at night. Brass sextant with pendulum artificial horizon. 1835-1845
Octant with an artificial horizon patented by John Syeds, London, about 1791, and possibly made by him. Lacquered brass frame, a polished brass limb. Marked on the frame: Ino Seyds | Patentee No 12. Marked on the brass case of the artificial horizon: Iohn Seyds's Patent. Brass scale from -2° to 99° every 20', measuring to 99°. Brass vernier to 1', zero at the right. There is no tangent screw; the clamping screw is on the back of the index arm. No shades found, but holes in the frame suggest there may have been index shades. Index-glass adjustment by screw; adjustment of the horizon glass by a lever, wing nut and a milled clamping screw. Adjustment of the third glass, for reflecting the bubble of the artificial horizon, is by lever, wing nut and milled clamping screw. Sight vane with two pinholes and a swivelling shutter; the vane can be moved along the right strut of the frame over a short distance by a milled screw, and clamped into position by a second milled screw. The horizontal position of the brass case containing the bubble level can be adjusted along the left strut of the octant frame by a milled screw, and clamped into position by a second milled screw. The artifical horizon consists of a bubble level that, when the instrument is held vertically, is reflected by the third glass into the silvered part of the horizon glass, when the horizon is not visible. in box... not seen, WMB Brass framed octant fitted with bubble artificial horizon and carrying case 1790-1799