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Brass framed repeating circle with case.

1815-1825

Double reflecting circle.

1850-1869

Brass framed reflecting circle.

1820-1825

Brass reflecting circle.

1865-1871

Hassler's reflecting circle, 11-inch diameter with counterpoise stand, by Troughton, London in case, no key [RAS No.43, Sheepshanks No.17]. Presented to the Royal Astronomical Society in 1857 by Miss Anne Sheepshanks sister of Rev. Richard Sheepshanks.

Hassler type reflecting circle with case.

1790-1826

Reflecting circle made by F.W. Breithaupt and Sohn, Kassel, Hessen, Germany, about 1870. Circular anodized brass frame, polished limb, a wooden handle. Signed on the index glass mount: F.W. Breithaupt & Sohn | Hessen Kassel. Inlaid silver scale from 0° to 140°, and twice from 180° to 80° every 20'. One index arm with a silver vernier at both ends, to 20", zeros at the right. The tangent screw, working against a spring-loaded stop, and the clamping screw are at the bottom of the index arm. Four half-coloured shades (two red, one green (broken), one missing); no horizon shades. Index-glass adjustment by screw; horizon prism without adjustment. Magnifier on a 120 mm swivelling arm serving both verniers, a frosted glass shade (missing). Threaded telescope bracket in two parts, fitted for correcting collimation error; perpendicular adjustment by rising-piece and a milled knob. Telescope (158 mm) inverted image, six parallel cross-wires and one at a right angle to them are engraved on a lens within the telescope; a rotating shaded eyepiece with choice of clear, green, red and blue. A prismatic eyepiece; some unidentified parts are missing. In a square fitted mahogany box containing a trade label for Breithaupt in Cassel and a MS list of contents.

Prismatic reflecting circle with case.

1865-1875

Double reflecting circle made by A. Hurlimann, successor to Lorieux, Paris, France, about 1900. Circular anodized brass frame and index arm, a hinged wooden handle. Signed on the brass limb: Lorieux, A. Hurlimann, succ.r a Paris (172). Inlaid silver scale from -5° to 195° every 30'. Silver vernier to 1', zero at the right. The index arm carries the index glass, the horizon glass is fixed on the frame. The tangent screw is on the front of the index arm; the clamping screw is on the back. Seven detached index and horizon shades (six green, one orange). Two index glasses, adjustment on both and on the two horizon glasses by square-headed screws and a detached key (missing) and by capstan screws. Magnifier (single lens) on a 65 mm swivelling arm. Telescope (100 mm), erect image, fixed in its bracket; perpendicular adjustment by rising-piece and a milled knob. Two shaded eyepieces (both green). A screwdriver; a magnifying glass; an adjusting key; an adjusting pin. A square fitted mahogany box (lid cracked) containing in the lid a trade label for A. Hurlimann, Ponthus and Therode, 6, rue Victor Considerant, Paris, and printed instructions in French for cleaning the scale. Painted on the front of the box: H.O [broad anchor] 202.

Brass framed double reflecting circle with case.

1895-1900

Reflecting circle made by Edward Troughton, London, about 1823. Signed on the index arm: Troughton | 219 | London. Polished brass limb with inlaid silver scale from 140° to 0° to 140°; the entire circle is divided every 20'. Three silver verniers reading to 20", zeros at the left. Circular lacquered brass frame with a wooden handle. A detached U-shaped bracket holds a second handle with a brass-lined threaded hole for a third handle, which can also be screwed on the front of the frame. Three rigidly connected index arms on the back of the frame, a double-ended tangent screw and clamping screw are on the back of one of the arms. Three shades (two red, one green); three horizon shades ( two red, one green). Index glass without adjustment; adjustment of the horizon glass by a screw and a capstan screw. One detached magnifier on a 55 mm swivelling arm, for all three verniers. Threaded telescope bracket in two parts, fitted for correcting collimation error; perpendicular adjustment by rising-piece and a milled collar. Telescope (77 mm) erect image; telescope (179 mm) inverted image two parallel cross-wires; extra draw tube (90 mm) inverted image; extra draw tube (90 mm) inverted image, two parallel cross-wires. Sight tube (132 mm); sight tube (131 mm, probably from a different instrument); three shaded eyepieces (one red, two orange); a magnifying glass. Three unidentified parts. Box not seen WMB. The circle is mounted on a lacquered brass column on a tripod stand with three milled levelling screws. The counterbalanced swinging mount can be locked into the desired position by milled screws.

Brass framed reflecting circle with case.

1820-1825

Reflecting circle made by Julius Wanschaff, Berlin, Germany, about 1875. Circular dark-brown and yellow-lacquered brass frame, with two wooden handles. Signed on the limb: Julius Wanschaff. Berlin 51. Lacquered brass limb with inlaid silver scale indicating from -5° to 130° and from 180° to 290°; the entire scale is divided every 10'. Two silver verniers to 10", zeros at the right. The tangent screw, working against a spring-loaded stop, and the clamping screw, are at the bottom of the index arm. Six half-glass shades (four red, two green), the shades can be moved away from the frame by a rising-piece; no horizon shades. Index glass and horizon prism without adjustment. Magnifier on a 130 mm swivelling arm, serving both verniers, a frosted glass shade. Threaded telescope bracket, perpendicular adjustment by rising-piece and a milled knob. Telescope (168 mm) inverted image, four cross-wires; extra draw tube (130 mm) inverted image, four cross-wires; extra draw tube (57 mm) erect image and a rotating shaded eye-piece with choice of clear, two red, and one green. A prismatic eyepiece, an adjusting pin. A square fitted mahogany box. The circle is mounted on a dark-brown and yellow lacquered brass column on a tripod stand with three milled levelling screws. The counterbalanced swinging mount can be locked into the desired position by milled screws. Used by Sir David Gill (1843-1912) during his 1877 expedition to Ascension Island to observe Mars and improve the determination of solar parallax and hence the Astronomical Unit.

Prismatic reflecting circle with case.

1875-1876

Reflecting half-circle made by Pistor and Martins, Berlin, Germany, about 1860. Brown and yellow-lacquered brass frame, polished limb, a wooden handle. Signed on the limb: PISTOR & MARTINS BERLIN. Marked on the limb: 664. Inlaid silver scale indicating from 350° to 0° to 130° and from 180° to 250°; the entire scale is divided every 10', measuring to 238°. Silver vernier to 10", zero at the centre. The tangent screw and clamping screw (both incomplete) are at the bottom of the index arm. Four half-glass shades (two red, two green), no horizon shades. Index glass without adjustment; adjustment of the horizon prism by capstan screws. Magnifier on a 130-mm swivelling arm, a frosted glass shade. Threaded telescope bracket in two parts, fitted for correcting collimation error by capstan screws; perpendicular adjustment by rising-piece and a milled knob. Telescope (183 mm) inverted image, two cross-wires (broken); telescope (85 mm) erect image; extra draw tube (133 mm) inverted image, two parallel cross-wires. Shaded eyepiece (red). A fitted rectangular mahogany box containing in the lid a trade label for Elliot Brothers, 449 Strand, London (18..-18-..)

Prismatic reflecting half-circle and case

1855-1865

Reflecting circle made by Charles West, London, 1817-1822. Circular lacquered brass frame and index arm, polished limb, two detachable wooden handles. Signed on the limb: C. West, 5. Cursitor St. Chancery Lane, London. Inlaid silver scale from 0° to 180° (four times) every 20'. Three silver verniers to 10", zeros at the right. The index arm carries the index glass; the telescope arm carries the horizon glass. The tangent screw and clamping screw are on the back of the index arm; two clamping crews are at both ends of the telescope arm. Four index shades (two red, one green); three horizon shades (two red, one green). Index-glass adjustment by screw; adjustment of the horizon glass by screw and capstan screws. Detachable magnifier serving two verniers on a 40 mm swivelling arm; a second, fixed magnifier is on a 25 mm swivelling arm. Threaded telescope bracket in two parts, fitted for correcting collimation error; perpendicular adjustment by rising-piece and a milled collar. Telescope (84 mm) erect image; telescope (152 mm) inverted image, four cross-wires; extra draw tube (57 mm). Sight tube (83 mm); shaded eyepiece (red); adjusting key; adjusting pin. Square fitted mahogany box containing in the lid a broadside of James Allan at no. 12 Blenvitts Buildings, Fetter Lane, London, announcing his new, improved, self-correcting dividing engine, and the prizes he received for this. The broadside was printed after 1811.

Brass framed reflecting circle with case.

1817-1822

18-inch reflecting circle made by "Troughton, London" with counterbalanced stand and tripod base with accessories

Reflecting circle with stand

1790-1826