Beginner's Corner
December, 1939

THE experienced telescope user is often less inclined to belittle the alt-azimuth type of mounting than is the beginner. With the equatorial type, because one axis is cocked over parallel to that of the Earth it is necessary to keep moving the telescope tube in only one direction as the Earth rotates. In the alt-azimuth, having the same axis perpendicular to the Earth's surface- that is, at some angle to the Earth's axis it is constantly necessary to move the tub in two: for example, over a bit (azimuth) and up a bit (altitude). In practice this isn't nearly so much of a bother as it sounds; while the mounting is simpler t build. The clean, trim alt-azimuth shown was built by J. L. Wagoner of Pittsburgh Pa. It has a 6" mirror and a 7" aluminum tube. The pillar is a piece of 4" brass tubing and the base and yoke castings are of aluminum.