Before the mountain which "Stellafane" surmounts was officially renamed Mount Porter the neighboring farmers sometimes called it Breezy Mountain. It is so breezy in winter that the builders of "Stellafane" anchored each of the house's four corners to the Granite State by means of a steel cable let into the rock, so that the building would stay in the state during the Vermont winters. Amateurs who have visited "Stellafane" may behold it now shrouded in white, with the dead grasstops waving above the snowbanks, in the photograph.

ALL three of the other photographs this month are of lads who have taken up telescope making, the hobby which appeals to young and old. The first is Winston Juengst, Box 43, Croton Falls, N. Y., aged 16, who says he has scratches and a turned-up edge on his mirror, but such a good paraboloid nevertheless that the telescope "supplies a real thrill." Juengst is studying astronomy with seriousness. He plans an eight-inch telescope next, but this appears to be contingent on parental permission as it seems he has also gone in for interior decoration, having redecorated the kitchen where he made the first mirror, in red of a shade suspiciously resembling that of optical rouge.

Richard W. Aldrich, 626 East Washington Street, Hoopeston, Illinois, aged 17 sends a picture of a four-inch mirror which "took a long time to make but finally came out all right." The total cost was not over seven dollars, he says, the eyepiece being from a "Kopton" optical set. He gets a magnification of 104 diameters.

Reed Knox, Jr., of University Terrace, Deland, Florida, says he "sends us a picture of his telescope so far." It is his third attempt. He dropped No. 1 on a concrete floor and No. 2 refused to polish out, but each time he gains impetus. As he is still no more than 12 years old he has time to beat the 200-inch record about to be hung up. When he grows up he says he expects to be a professional astronomer. Probably Knox is our youngest amateur. Who claims to be our oldest?

LAST month we promised to publish an abstract of an article by Professor A. E. Douglass of the University of Arizona entitled "Atmosphere, Telescope and Observer." This appeared in Popular Astronomy for June, 1897. Our abstract was sent to Professor Douglass with the idea that he might wish to alter it in the light of later experience, but he found nothing in it to alter. After all, however, the matters involved are basic and not a bit different in 1929 than in 1897, and therefore we make them available to our readers. Professor Douglass writes:

"Every astronomer knows that good seeing is not a matter of clouds and that the definition does not become superb merely because the atmosphere has become clear and perfectly transparent; on the contrary a certain amount of haze sometimes improves the seeing.

"Every possessor of a fair-sized telescope, has at hand a means whereby he may study the more obscure atmospheric conditions which accompany good and bad seeing and, at least in some cases, determine whether bad seeing is due to local conditions which may be evaded by moving a few miles, or to general conditions which may require a large change in latitude to correct. The means consists simply in placing the eye directly in the focus of the objective and watching the streams of air pass by overhead.

"The currents cast, as it were, their shadows on the objective and as all the light is concentrated in the focus, the eye can, without changing position, see all the irregularities in illumination which take place over that area, that is, in the cylinder which extends from the lens to the limits of our atmosphere in the direction of the star. In the ease of a planet of sensible diameter this volume is a truncated cone with its smaller end at the objective, instead of a cylinder. These differences of illumination are not real shadows but are condensations or rarefactions of light caused by the refractive power of the air. When, therefore, the objective brings all the light to a focus the light from certain portions of the waves comes together inside the principal focus and from other portions outside, so that an eyepiece may be placed behind these foci at proper distances and the waves seen through it.

"The currents of course are usually observed at night but they may be seen in the daytime by using a small diaphragm at the focus to exclude the greater part of the light of the sky. By day they are extremely handsome.

"In order to understand the subject better, let me cite a few familiar cases of the same or similar phenomena. The most ordinary instance is met with in sunlight upon shallow water. There, beneath each rising wave, the light is condensed, while beneath each trough the light is enfeebled. At a certain depth, depending on the character of the waves, the contrast between the crest and the trough is most marked. Upon going deeper the difference decreases, leaving finally only light and dark patches. I conceive the waves in the air to be very similar in their action, although having a different origin and with an extremely slight refractive power. These so-called waves are lines of irregular refraction in the air due to non-uniform density. The irregularities in density are due, I am convinced, to irregularities of temperature.

"Bearing in mind the foregoing facts in regard to the constant presence of air waves which are only a few inches apart and have a measurable refractive power, it is no difficult matter to deduce the conditions under which certain apertures become preferable."

Professor Douglass' discussion will be concluded in next month's number, when he will point out some limitations of the larger sizes.-A. G. I., Tel. Ed.

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