• Scale: The 177mm diameter circle is fixed, and the table and telescope movements are completely independent of each other. Both movements can be read to 30 seconds of arc by means of double ended verniers. Both rotations have fine adjustment screws, and release of a clamping screw enables coarse adjustment to be made by hand.
• Collimator: Mounted on fixed pillar & fitted with 178mm focus achromatic objective, 32mm clear aperture. A unilaterally adjustable slit, 6mm long is also fitted.
• Telescope: Mounted on moveable pillar and fitted with 178mm focus achromatic objective, 32mm clear aperture. Also fitted is a x15 Ramsden eyepiece and a glass crossline graticule. Both the telescope and collimator have rack and pinion focusing.
• Prism Table: The table is marked with lines to assist placing the prism with respect to the table levelling screws, and has interchangeable clamping units for the prism and a diffraction grating.
Standard accessories supplied:
• 1 dense flint glass prism
• 1 prism clamp
• 1 diffraction grating holder
• 1 watchmaker’s eyeglass
• 1 tommy bar for adjusting optical axes
• 1 polished hardwood case
• 177mm diameter circle
Allows readings to 30 seconds of arc