An economically priced instrument, which is nevertheless capable of much useful quantitative work. The main structural parts, including the collimator and telescope bodies are heavy castings, other metal parts being bright plated. Scale: 170mm diameter, divided 0 to 360° × 1°, independently rotatable with locking screw. A spring-loaded vernier scale attached to the telescope mount provides readings to 0.1° (6 minutes of arc). Collimator: Mounted on fixed pillar with axis adjustment. Objective lens has 150mm FL, an aperture of 21mm and is carried in spiral focusing system. Unilaterally adjustable slit 6mm long. Telescope: Mounted on moveable pillar with adjustment, locking screw and axis adjustment. Objective lens has 170mm FL, 21mm aperture and is carried in a spiral focusing system. Ramsden eyepiece with cross wires and locking ring focus adjustment. Prism Table: The table is provided with three leveling screws and has lined marked to assist placement of prism. Standard Accessories Supplied: 1 prism clamp for prisms up to 40mm high, 1 diffraction grating holder, aperture 25 × 25mm, 1 small screwdriver, 1 tommy bar for axis adjustment.
- Scale: 170 mm diameter
- Aperture: 25 × 25 m