abstracted from Manual of Celestial Photography by Edward S. King ©1955
King's formula, in terms of the rotation period of the hour axle in universal minutes is, when the hour axis is aligned on the refracted pole:
There is a sensible diference in the drive rate for the hour axis aligned on the true pole:
Gamma is the elevation of the hour axis above the true pole. At the refracted pole:
At the true pole: hence
therefore: mean minutes per revolution of the hour axle.
where n is the RA worm ratio.
This page was created by SimpleText2Html 1.0.2 on 29-JAN-2006