The base, integral with the collimator tube support, carries
the swinging telescope arm pivoted on a bearing with springloaded
end thrust plates; this type of bearing eliminates any slack
which would otherwise develop with wear. The collimator and
telescope tubes are one piece precision casting in light ally,
concealed helical action focusing devices are provided. The
collimator slit with spring loaded jaws is of anew and robust
design which ensures retention of the initial accuracy.
The graduated prism table support, 18 cm dia, is divided in
degrees, the vernier, reading to 0.1 , is fixed to the telescope
arm. This arrangement permits easy estimation to 0.05 from
the conveniently positioned vernier scale. The fully adjustable
prism, table, 705 cm dia, is engraved with concentric rings,
which facilitate correct location of a prism and has two screwed
holes for the attachment of prism and grating holder, to accommodate
prism upto 25 mm high.
Large diameter clamping knob are fitted for movement control
and fine adjustment is provided for the telescope. All bright
parts are chromium plated with the base and tubes in synthetic
Dimensions overall: 51 x 23 x 22 cm length x width x height.