#Cat. No. L4020 LABORATORY SPECTROMETER.# This instrument is very rigid and
accurate in construction and every part of its design has been carefully
considered. The circle has a diameter of 15 cm. and the two verniers read
to 20 sec. It is fitted with protecting plate which adds greatly to the
value of the instrument if put in the hands of students. The graduation is
on solid silver. The verniers are fitted with adjustable magnifying
glasses, the telescopes have an aperture of 25 mm., focal length of 200 mm.
A horizontal adjustment for the telescope is provided. No provision is
made for radial adjustment, which correction is made before the instrument
is sent out. The slit is accurately constructed; the jaws are of German
silver and it is provided with comparison prism. The eye end of the
observing telescope is of standard size so as to receive our micrometers
M201 or M202, or the Auto Collimating eye piece (Lamont & Abbe) M540. Gauze
eye piece is fitted to the instrument. The prism table and observing
telescope have independent movements and each is provided with clamp and
tangent screw. The prism table can be clamped to any part of the vernier
plate. The prism holder has convenient leveling arrangement and will hold
prism up to 35 mm. in height. The instrument is arranged to receive Fuess
centering apparatus and crystal holder. A 60 degree heavy flint glass prism
of best optical quality is included.