"My first attempt was a mirror of six-inch aperture and 50-inch focal length. The greatest difficulty encountered was the inability to construct a perfect pitch lap. However, the mirror was parabolized in due time, and mounted. The results were very satisfactory, as the telescope gave beautiful definition of all celestial objects which I was able to pick up.

"After finishing my first mirror I decided to construct a larger instrument which would have an equatorial mounting provided with setting circles. This mirror is 12 inches in aperture and 96 inches in focal length It is a considerably larger job than the earlier one, but the results are far superior.

"It required 18 hours to grind and polish the m1rror, and many more to produce the required correction. To my great surprise the silvering proved to be the most obstinate problem of the entire process, although I had experienced no trouble silvering my first mirror. It cost five dollars for materials and much worry and study before the desired degree of success was obtained. (An average experience. Silver is fickle.-Ed.)

"The mounting is of the conventional design of Mr. Ions. This was adopted because it could be constructed with very little machine work. A portable mounting should be as light as possible, and for this reason I constructed the counterweight on an extension of the declination axis which permitted the use of a comparatively light weight and enabled the mounting to be more easily moved. This telescope gives perfect definition and shows a beautiful image of Saturn or Jupiter.

"I have doubly profited by my experiences as an amateur telescope maker. The construction of the mirror itself was so intensely interesting that I would feel repaid if there was no result other than the production of a perfect paraboloidal curve. But I have also been admitted into the wonders of the heavens. Before I constructed my first telescope I neither knew nor cared anything for astronomy. I now spend many evenings in exploring the sky, and although I do not know much about the movements of the celestial bodies as yet, I am diligently studying the science and hope to learn more."

Mr. E. T. King, 301 West Lincolnway, Jefferson, Iowa, sends us a photograph of his six-inch telescope. This is the Springfield type. His method of supporting the polar axis, as shown in the illustration, is unique.

What the average newspaper reporter will do is, of course, beyond scientific, or even unscientific, prediction. One Des Moines Sunday paper states that Mr. King can now sit in his back yard and "speculate what forms of civilization the moon and stars have"! Still, this is little worse than a claim made by one of our readers-a telescope maker, at that-who is certain that he sees volcanic eruptions on Capella! He also claims he sees vegetation and whathave-you! He does not seem satisfied with our suggestion that he clean his eyepiece and read up on the theory of resolving power. The sun is the only star on which even the most powerful telescope will reveal detail; or, in fact, even the actual disk itself.

Mr. P. O. Parker, Cohutta, Georgia, is the first to make use of a Ford front wheel assembly for a polar axis. He writes: "I enclose a photograph of my telescope which was made according to the instructions in the book 'Amateur Telescope Making.' I had quite a bit of trouble figuring the six-inch mirror, but finally got a fair job. With eyepieces of one inch, one half inch and one fourth inch it gives excellent results on the moon and planets, and fairly good on double stars.

"The mounting was made from a Ford front hub assembly. The upright was cut at proper angle for latitude, and hub bolted to it for polar bearing. The spindle acts as declination bearing. The declination axis was the only part requiring any machine work, and it very little. The counterweight was moulded of babbit. The wheel just above the counterweight is a declination clamp. A four and one half dollar worm and gear from the Chicago Stock Gear Works, whose advertisement appears in each issue of the SCIENTIFIC AMERICAN, made an excellent slow motion in right ascension. The entire mounting and work cost about ten dollars."

This front hub assembly stunt impresses us as an ingenious arrangement. It provides a fitting funeral for a model T Ford.

Dr. J. J. Byl, 430 South 13th Street, San Jose, California, writes that he is experimenting with lunar photography, using the telescopes he described in the issue of last February, on page 177. As others are no doubt doing the same thing it is hoped that a number of photographs of the moon will be sent in for publication in some one issue. Another issue will be devoted to spectroscopes, providing enough photographs of those made by amateurs reach us within a few months. Next month's space will be devoted largely to grinding and polishing machines made by amateurs.

This month we have altered the standard heading of our department from "The Back Yard Astronomer" to the form you see at the top. This does not, however mean we have become too "high hat" to inhabit the back yard during our observation periods; in fact, we have retained Porter's sketch of the typical back yard with all the trimmings. "The Amateur Astronomer" gives us a little more scope and dignity-as if we needed that quality!

We are making a collection of the inevitable misprints and errors found in A. T. M., as it is desired to compile an erratum sheet. We therefore request those who have found any such slips to advise us, as there are doubtless some which we have missed.

Amateurs in Pittsburgh have been organized into a club which meets on alternate Sundays at the homes of the different members. The president of this club is Chester B. Roe, 624 Hemlock Street Avalon, Pennsylvania.

Now that Old Man Winter is off the job, Young Man Mosquito is on.- The amateur astronomer is beset with troubles the year around-unless he happens to live in California or places where neither nuisance exists. Ye Tel. Ed. undergoes two annual changes of mind in this regard: in summer, when slapping the famous Jersey mosquito between short peeps at the eyepiece, he thinks there will at last be peace when cold weather comes; but in cold weather he must slap still harder to prevent death by freezing. Maybe, after all, the best place to be is down cellar, making more telescopes to try out later and discover that the cold or the mosquitoes render it advisable to retreat to the cellar and make another telescope to . . . Well, why do we amateurs make telescopes, anyway?-A. G. I., Tel. Ed.

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.