HERE is a letter from A. Wade, mechanical engineer, connected with the lndustrial Accident Commission of the Department of Industrial Relations of the State of California, 906 Associated Realty Building, Sixth and Olive Streets, Los Angeles. "In June, 1926, you published the picture of my first telescope. The present photograph shows my latest. Nothing is being said about the score or more of intermediate ones, though only four pieces of glass and three different mountings were involved in the struggle.

"The picture tells most of the story, though it may not be obvious that the tube can be rotated in the mounting. The mirror is 11-1/4 inches in diameter with a focal length of 100 inches. The little electric motor that drives the polar axis is in the bottom of the pier.

"Some time ago you invited amateurs to tell what their telescopes would do in the way of definition, but I have seen but little on this point. (Reason: nothing came. -Ed.) Perfection is not claimed for this creation, but the components of double stars separated by one second of arc can been seen; for example, Eta Orionis. I can also see the chain of lunar craterlets near Copernicus, and the less conspicuous indentations in the submerged crater Stadius.

"In the picture of the telescope the bright line near the worm gear is part of the sidereal circle mounted on the gear. The hour circle is on the polar axis."

Mr. Wade cut the slots in the tube to ventilate it better, with the purpose of gaining improved seeing. He says he has not yet discovered any improvement.

THE first telescope tube in the universe made of an organ pipe was used by Stephen Stoot, connected with Casavant Fréres, pipe organ builders, St. Hyacinthe, P. Q., Canada, on his telescope. He writes: "In addition to the vast amount of information on mirror making contained in the SCIENTIFIC AMERICAN book 'Amateur Telescope Making' I received some valuable hints from Mr. H. L. Rogers of Toronto. He has made four telescopes, three being of six-inch diameter and one of 12-inch. The telescope works well and results were beyond my expectations.

"The tube is a portion of a 6-1/4 inch organ pipe of hard-rolled zinc, 16-gage and may be rotated in its cradle of maple. The polar axis was made from a discarded check-valve case from the old steam heating system in our factory. It had an inclination of 45 degrees, and as the latitude of St. Hyncinthe is 45 degrees 37'15" I decided to use it. The rest of the mounting is made of pipe fittings. The slow motions are from an old-time gramophone drive. For the base a block of concrete two feet square at the bottom, one foot square at the top and four feet high was set in an excavation four feet deep. Embedded in its center is n three-inch iron shaft surmounted by n flange seven inches in diameter. Upon this platform the rest of the mounting is constructed and in such a manner that it can be removed and taken indoors. When the upper part of the mounting and telescope are removed the cell is left on top of the pillar. The parts may seem heavy for a six-inch telescope but I have found it difficult to err on the side of rigidity if one wants comfort in observing anything in the heavens."

Mr. Stoat's insistence on rigidity surely requires no apology and his mounting contrasts favorably to some of the "India rubber" mountings we have seen. As for keeping the mirror out of doors, that is where we keep ours-right on top of the tube of our 10-inch Springfield mounting, covered by a tin cap, and always self-adjusted to the temperature.

THE simple wooden "spinal column" mounting for a small mirror, described by Russell W. Porter in "Amateur Telescope Making" (page 28-30), bas been expanded to take a 12-inch mirror of 99 inches focal length by George F. Walker, 920 Twelfth Street, Bremerton, Oregon. Mr. Walker writes: "The cement, sand, and gravel cost about two dollars. I cut the steel reinforcing rods from old bed ends. A bronze bushing 14 inches long, cast in the concrete, provides a bearing for the polar axis; it came from a junk pile and happened to be n snug fit for the 1-1/2 inch cold-rolled steel axis. The yoke is n piece of three-inch steel channel. Two split bearings cast from babbit metal carry the l-1/4 inch declination axis and the latter has a flange which bolts to the wooden "backbone" of the telescope. Notice the concrete counterweight cast into a pipe which adorns the other end.

"The declination and polar axes are driven by two 360-tooth worm gears, and for moving the declination axis the worm lifts out of mesh. Just now I am casting about for a cheap, husky clock to keep the zero mark pointing at the celestial meridian.

"The backbone of the telescope is a good clear two-by-six cut from Washington's famous Douglas fir. The mounting is rugged and relatively steady but I notice that when anyone is walking nearby, the earth itself is only relatively steady."

WE never had flattered ourselves that telescope making was as serious a disease as stamp collecting (our wife collects stamps and we therefore speak advisedly) but the impossible has now come to pass. A stamp enthusiast, the secretary of the American Philatelic Society, Dr. H. A. Davis, 3421 Colfax A, Denver, Colorado, has made a telescope, and sends in a picture of it. The accompanying confession reads: "I was one of the first to purchase 'Amateur Telescope Making,' in 1926 and have finished a telescope after all this time. Never have I put more than 30 minutes' work on the job at a given time. In fact, it was done principally in five and ten minute periods, demonstrating that a man with absolutely no spare time (seemingly) can accomplish much by making use of short snatches of opportunity.

"The mounting is an alt-azimuth and has one worm gear working directly in the quadrant cut from an auto ring gear. For the slow motion in azimuth I used a stock brass plate gear of 16-pitch, with worm to match. The mounting is made of sugar pine."

Mr. Davis's telescope is trim and workmanlike. We hope the publication of the above evidence of his partial apostasy from stamp collecting will not result in his subjection to trial by the philatelists for worshipping false gods. Besides, there may also be telescope addicts who have indulged, on the sly, in stamp collecting. But when it comes to being addicted to both diseases it seems almost like leading a double life.

We have three lines left-just enough to beat the tom-tom about a big book every amateur has cried for. See page 355, quick!

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.