Reflecting Circle, by Troughton, London, c. 1810

Troughton-type reflecting circle with squared lattice support and inlaid silver scale, three-armed index, each arm with a vernier, one with clamp and tangent screws; index mirror, horizon glass, two sets of pivoted shades, 3 wooden handles, telescope with lateral adjustment, bubble level. Mount for pillar stand with tribrach base, two counter-weights. Mercury artificial horizon in separate mahogany case.