Scale The 150mm diameter circle with protective plastic shield is fixed to the telescope movement and the table is attached to the double ended vernier which reads to 1 minute of arc. Both telescope and table rotation fine adjustment screws and release of a clamping screws enables adjustment of both movements to be made by hand.

Collimator Mounted on fixed and fitted with 178mm. focus achromatic objectives, 25mm clear aperture. Also fitted is a unilaterlly adjustable slit, 7mm long.

Telescope Mounted on moveable pillar and fitted with 178mm. Focus achromatic objective, 25mm, clear aperture. Also fitted is a 8x ramsden eyepiece and a glass crossline graticule. Both the telescope and collimator have rack and pinion focussing. Means are provided for levelling the axis of both optical units and for squaring them to axis of rotation.

Prism Table The table is marked with lines to assist placing the prism with respect to the table levelling screws.

Standard Accessories Supplied

1 prism clamp, 1 diffraction grating holder, 1 magnifier, 1 tommy bar for adjusting optical axis, 1 wooden case.