#Note.#--This spectroscope can also be used on a support for laboratory
work.
#Support# for above spectroscope. Price #$4.50#
#A602. Spectroscope# for telescopes from 6 in. to 18 in. aperture and
detailed description on application.
[Illustration: A 701]
#A701. Chronograph# for physical and astronomical work. This chronograph is
designed to meet the demand for a medium sized, well-made and accurate
instrument of this kind and has given very good satisfaction. The cylinder
is 15 cm. in diameter 25 cm. long, driven by strong, carefully made clock
work, fitted with friction governor. Two different speeds for the cylinder
can be obtained by means of change gears. The slow speed of the drum is one
revolution per minute, and at this speed the drum will run for a full hour.
The fast speed is 30 seconds per revolution. The carriage is driven by
means of a screw, the nut of which is made to disengage easily.