"The amateur telescope makers' column in the SCIENTIFIC AMERICAN has interested me for a long time, but it was only last year that I really got the hunch that perhaps I could make a telescope myself and enjoy the wonders of astronomy apart from picture books. Now I enclose two snapshots of my eight-inch equatorial reflector successfully constructed during spare time from the rules of the game laid down in that invaluable tome, well known in your page as A.T.M.' A friend, Mr. Alchin, also made an eight-inch mirror with me but has not yet got it mounted.

"The mounting is the H.F. type (Henry Ford) with circles. I find that the Ford axles, while probably strong enough to carry a much larger instrument with ease, -are too light and elastic. This causes undue vibration (Ford all over!) in light winds.

"The run-off shed was constructed very cheaply out of some old three-ply material nailed on the inside of the light battens which form the framework. The rails are three by two scantlings nailed to pegs, driven into the lawn, and the shed runs on four ball-bearing furniture castors. It is kept on the track by wooden lugs screwed to the bottom battens and projecting down inside the rails. The shed can be run off and the telescope put in use within a minute.

"My telescope, since its completion, has started a third eight-inch mirror on the rougey road (not finished yet) while a fourth amateur is definitely sickening for the trouble. He has bought 'A.T.M.' I would be glad to hear from any others in New Zealand who have taken up telescope making in earnest. Greetings from N.Z. to U.S.A. I have very happy memories of two years spent in your country, 12 years ago."

EQUALLY distant (on great circles) with New Zealand from our own land is India, where P. J. Chinmulgund of 3'33 Sadashir, Poona 2, Bombay Presidency, has made a six-inch reflecting telescope from the instructions in the SCIENTIFTC AMERICAN book "Amateur Telescope Making." Here is what he writes:

"The mirror is a six-inch of 57.5 inches focal length. I had some trouble in obtaining the materials, as they are of an out-of-the-way type in this country. As I could not get the very grades of Carbo stipulated, I used Nos. 90, 220, FFF; and finished off with emery. This greatly curtailed the time required for polishing, which was complete in three and a half hours. Though my lap was a bubbled one and the grooves irregularly cut by a saw, I obtained a beautiful and even polish.

"Finally I parabolized in six minutes by overhang. I worked for two minutes each time and waited for half an hour to allow the disk to return to the room temperature. The shadows looked exactly like those shown in the book. The mirror was left a little under-corrected, as advised.

"I required just a month to finish the mirror. I never worked for more than an hour at a time, and at times I left off working for a couple of days on end.

"I did not succeed in silvering at the first attempt but finally I did succeed in securing an adequate coat. I had to use ice to keep the temperature of the solutions down.

"Pipe fittings are used in the mounting and they work very smoothly. The counterweights are a pair of heavy old dumbbells, which serve their purpose admirably. As there is no suitable place for mounting the instrument permanently, I have mounted it temporarily on a vise.

"The total cost was surprisingly low-about rupees 40 at the most, i.e. 13 dollars, approximately.

"The diagonal is a piece of flat plate glass, and functions excellently. I could not get a suitable eyepiece at any shop here, so I constructed one myself. I had some small lenses and assembled them with the necessary separations. The eyepiece contains three lenses-two double-convex and one plano-convex, and is of about one inch e.f.l. It gives a flat and colorless field.

"There are many advantages that nature offers to the amateur in India especially in Poona. The temperature is always quite uniform. Hence I could work in a living room, and a cellar was unnecessary. The skies also are quite clear nearly all the year 'round, and the constellations shine with unusual brilliancy.

"I don't know, but I think this is the first home made telescope in India-at least in Bombay Presidency. Some idea of the slow pace at which I had to work may be had from the following: I ordered the book

in August, got it in November, began the job in June and completed the mounting in October! A whole year from start to finish! "

DR. H. PAGE BAILEY, the Riverside, California dentist who designs and makes a new telescope every morning before breakfast, has constructed for M. Nagata (discoverer of Nagata's Comet) a neat nine-inch electric-clock-driven reflector of the split ring equatorial type. This type of mounting is unusually trim, compact, and mechanically superior, its operation being very smooth Note the neat, accessible hour circle on the face of the ring.

Dr. Bailey has originated a unique mounting for a refractor or reflector, shown in the illustration above (model only) in which there are two split rings, each on rollers, one bearing down on its exterior, the other up on its interior. The tube is self-balancing. As no pier is in the way there is no reversing, and there are no blind spots in the sky. Russell W. Porter says he believes this mounting is wholly original with Dr. Bailey. The split equatorial ring principle itself was first embodied in a telescope by Mr. Porter when he made, in 1922, about 50 of the well-known "Porter Garden Tele-scopes" having this feature, the ring turning on rolls. It is a pleasing design and might have been embodied in the 200-inch telescope, but it was found there was no way to get the big mirror in and out!

A photograph of the Orion nebula made by Dr. Bailey with a similar telescope (an eight-inch of f 3.6) is reproduced. The photograph, which was made by placing a plate-holder in the primary focus and exposing 18 minutes, covers a field about a quarter degree in width; note the absence of coma at the edge of the field! Those star images are round.

The Society for Amateur Scientists (SAS) is a nonprofit research and educational organization dedicated to helping people enrich their lives by following their passion to take part in scientific adventures of all kinds.