When the inexperienced amateur purchases an equatorial with circles,
he should not be without the third edition of “Chamber’s Handbook of
Descriptive Astronomy,” which, besides being an excellent book in
other respects, is a really practical guide to the use and
application of the Equatorial, and is indispensable to the beginner.
He will there find the fullest details of the adjustments to any
degree of exactness. Besides many other matters he will be
instructed in the use and application of apparatus to the perfect
Equatorial, including all kinds of eye-pieces, micrometers, &c.,
&c., as well as other optical instruments and accessories.
The Equatorials described in this catalogue are provided with every
means of adjustment. The cradle contains powerful screws to set the
line of sight at right angles to the declination axis, and shifting
screws to place the polar axis in the meridian and to the correct
elevation, and with care and a few experiments with the adjustments,
and by observations of some catalogue stars, the various adjustments
will soon be correctly made, and the verniers set accordingly.