Consists of heavy cast metal with bright plated fittings 150mm dia scale with protective cover and acrylic windows to read verniers, is fixed to the telescope movement. The table is attached to double ended venires reading to 1 minute of arc with magnifiers provided for the purpose. Both telescope and table rotations have fine adjustments. Collimator is on a fixed pillar with 175 mm focal length achromatic objective of 25 mm aperture and an adjustable slit. Telescope is on a movable pillar with 175 mm x8 Ramsden eye-piece. Prism table is marked with lines to assist prism placement and has three leveling screws. Accessories : One prism clamp, diffraction grating holder & one Tommy bar for axis adjustment, in wooden case.