Optics

Vernier reading to 30 seconds of arc. The 175 mm dia. scale is fixed. The table and telescope movements are completely independent of each other and read to 30 seconds of arc by means of double-ended verniers and magnifiers. Both rotations have fine adjustment screws. Coarse adjustments can also be made by release of clamping screw. Collimator is mounted on a fixed pillar and is fitted with 175 mm focal length. Achromatic objective with 32 mm clear aperture and a laterally adjustable slit 6 mm long. Telescope is mounted on a movable pillar fitted with 175 mm fl. achromatic objective of 32 mm clear aperture and x 10 Ramsden eye-piece with a glass cross line graticule. Both the telescope and collimator have rack and pinion focusing and can be adjusted for leveling the axes of both units as well as for adjusting to the axis of rotation. Prism table is marked with lines to assist prism placement and has three table leveling screws. It also has an interchangeable clamping unit for the prism and diffraction grating.
Complete with prism clamp, diffraction grating holder and a Tommy bar for adjusting optical axis. In case.

For measurement on two axes, with horizontal and vertical scales, heavy stand with leveling screws, and a carriage fitted with micrometer screw for fine adjustment. Another sliding carrier is provided on vertical bar also with micrometer screw for fine adjustment. Microscope tube is fitted with rack and pinion focusing. Stainless steel scales and verniers, horizontal scale 160 mm with vernier reading to 0.01 mm and vertical scale 140 mm with vernier reading to 0.01 mm. Ramsden eye-piece x 10 with crossline graticule and 50mm focus objectives. Magnifier is provided to read vernier.