ADJUSTING THE LATITUDE ANGLE OF AN OPTICAL TELESCOPE
The latitude angle of an optical telescope can be aligned by setting the optical axis parallel to the hour angle axis (declination = 90 degrees), and aiming the telescope at the north (or south) celestial pole.
The north celestial pole is within one degree of the star Polaris (the "north star").
Image of star circles around Polaris copyright © by David Malin, Anglo-Australian Observatory, Epping NSW, Australia. Reproduced by permission.
http://www.aao.gov.au/htdocs/images/