instrument is designed for high performance student use. It
has cast aluminium alloy main structure. The collimator tube
is mounted on the fixed pillar and telescope tube on the moveable.
Both the collimator and telescope have 175mm focal length,
32mm clear aperture object glass at their one ends. The collimator
has a precision slit 6mm high and telescope has Ramsden’s
eye-piece 15X at their other ends. Both collimator and telescope
have rack and pinion focussing and means for levelling their
axes and squaring them to the axis of rotation.
The scale 127mm diameter with protective shield is fixed to
the telescope movement and the prism table is attached to
the double ended vernier which reads to 1 minute arc. Both
telescope and table can be rotated independantly by hand about
the same vertical axis. These can be clamped at the desired
positions and adjusted precisely with the help of fine adjustment
Prism table is marked with lines to assist placing the prism
with respect to the table levelling screws and has screwed
holes for fixing prism and grating holders. Prism holder can
accomodate prisms upto 38mm high. Supplied with prism holder,
grating holder, magnifier glass, tommy bar for adjustment
of optical axis and dense flint glass prism, equilateral 32x32mm.
In plywood case.