A paired pillar frame transit theodolite.
Base-Dia. 5" (12.7cm) graduated anti-clockwise to 360 by 30', with three vernier scales 0-30, one vernier fitted with a slow-motion screw and clamp. Fitted with three levelling screws. A tripod mounting socket with four levelling screws, clamp screw and azimuth slow-motion screw is provided which can fit on a spigot at centre of underside of base.
Compass-Dia. 3.25" (8.3cm) mounted at centre of base. Fitted with a steel edge bar needle, pointed at each end 2.6" (6.7cm) long, with a jewelled cap at centre. Graduated to 8 points (E & W points transposed) and anti-clockwise to 360 degs. Needle lifting mechanism missing.
Paired pillars-Two pairs of brass pillars 5" (12.2cm) long, mounted on base at E & W positions. "Y" bearings are mounted at top of each pair, one "Y" fited with two vernier scales to 1' and a clamp with slow-motion screw, for use against the vertical circle.
Vertical circle-Dia. 4.1" (10.3cm) graduated anti-clockwise to 360 degs by 30', mounted on one side of telescope spindle.
Telescope-Length 8" (20.3cm) erect (cross wires missing ) with O.G. lens cap. A spirit level 4" (10.2cm) long is attached to top of telescope, another 2" (5.1cm) long is suspended on two brackets below. Three eyepieces, slide filter and two dark eyepiece caps are contained in box.
Variation compass-Length 7.25" (18.4cm) with a steel edge bar needle 6.25" (15.9cm) long mounted in box.
Artificial horizon-Dia. 2.6" (6.6cm) dark glas type, with spirit level and three levelling screws contained in a red leather case.
In fitted wooden box 10.5 x 7.8 x 7.8" ( 26.7 x 19.7 x 19.7 cm) containign a magnifying glass, tommy bar and various manuscript directions for use and stowage of instrument in box.