made to swivel in the base casting, so that the polar
axis may be easily set and firmly clamped at an angle from horizontal to
vertical. A level is fitted to the tripod top and a graduated arc is
fastened to the clock case. If the polar axis is set vertical and the worm
wheel unclamped, the instrument is transformed into an alt-azimuth
mounting. This feature will be found to be a great convenience especially
for terrestrial observations.

Both the polar and declination axes are carefully fitted to their bearings
and carry finding circles. The right ascension circle reads to 5 min., the
declination circle to single degrees. The declination axis is fitted with
clamp screw which is within convenient reach.

The clock has ample power and is enclosed in a heavy case which protects it
from dust and injury. It is driven by two strong springs and will run about
12 hours without rewinding. A lever for starting or stopping is provided.
Motion from clock to polar axis is transmitted by means of a set of bevel
gears and worm and worm wheel. The worm wheel is held by friction to the
polar axis so that the telescope can be moved without loosening any screw
and without affecting the clock. The clock will give steady and accurate
motion to the telescope and with ordinary care it will keep in good repair
for years. A slow motion adjustment independent of the clock is fitted to
the polar axis.

With the instrument are furnished three celestial eye pieces giving a
magnifying power of about 50, 100 and 150 diameters respectively.

The instrument is easily portable, the total weight of a 3" telescope being
about 60 lbs. yet it is made heavy enough, and the material well
distributed to insure strength and steadiness. Workmanship and finish of
the instrument are the best. The brass parts are either lacquered yellow or
bronzed. The iron parts are durably enameled and all exposed steel parts
are nickel-plated.

#A120.# Telescope of 3" aperture. Price #$190.00#

#A121.# Telescope of 3 1/2" aperture, the same as above but the bearing
parts made proportionally heavier. Price #$240.00#

#A122.# Telescope of 4" aperture. Price #$320.00#

For accessories see page 11.

#Note.#--An iron column can be provided for above telescopes in place of of
the tripod, at an extra cost of $20.00.

[Illustration: A 130]

EQUATORIAL MOUNTINGS ON IRON PILLAR WITH DRIVING CLO