細節
A fine lacquered brass transit theodolite, unsigned, the twin 9½ inch vertical circles with inset silvered scales, the telescope with lens cap, rayshade, micrometer fine adjustment with vernier, the axis hollowed, fitted with lenses and screw caps, the hardened steel end shafts located on double sprung "Attwood's" principle friction mounts, the axis caps numbered 1 and 2 surmounted by acorn finials, or with alternative graduated cross bubble bridge with adjustable reflecting mirror, the iron vertical supports incorporating the vertical circle lock and tangent screw fine adjustment, fitted with twin telescopes; to one side a vertical quadrant support fitted with a graduated level and two horizontal telescopes with micrometer fine adjustment, the vertical bar with key and knurled screw fine adjustment; the other with leaded compensating balanced weight with additional fine adjustment screws for use when necessary, the vertical supports moulded together with the massive horizontal plate attached to the double vernier read-out with twin telescopes, a bracket incorporating the tangent screw fine adjustment and lock, the chamfered silvered horizontal circle fixed to the iron base plate with three adjustable levelling screws, overall height - 25in. (63.5cm.)
See Front Cover illustration (2)