The first two are the straight-line type listed by Scanlon in the table of types at the end of his chapter on observatories, in the new book "Amateur Telescope Making-Advanced."

THE one in Figure 1 was built by Clarence T. Jones, architect, 210 Glenwood Drive, Chattanooga, Tenn., to house his 12" Newtonian. Two months ago we also published a description of a 20-3/4" Cass and observatory built by Jones and his sons Arthur and Bruce, with Paul Lewis, secretary of the local Barnard Astronomical Society. It now appears that Barnard was a native, not of Chattanooga, as was then stated, but Nashville, but that there are Barnard Astronomical Societies in both cities.

ASCENDING one flight we reach the "penthouse" observatories, the one in Figure 2 being the work of William Mason, 1303 Lakeview Ave., Lorain, Ohio, author, by the way, of the chapter in ATMA on mountings (p. 361). Mason says of his observatory: "1 built it for my 12" telescope [the one shown in ATMA, same page-Ed.], and it is 10' by 10' by 6'2" and 6'8"-the two heights given being due to the slope of the garage roof on which it is built. The covering is '3V' sheet iron painted with aluminum paint. The telescope is mounted on a base of 12'' seamless pipe filled with sand to lower the vibration period. No part of the garage or observatory touches it. Before I built it I thought I would like this type better than a dome; now I know I like it better."

ANOTHER penthouse observatory atop a garage is that of Charles A. Morrison, 39 Radcliffe Road, Rochester, N. Y. (Figure 3). He sends no description but the photograph suffices. The dome is 7' in diameter and is made of galvanized iron.

AMONG the trials and tribulations of an amateur astronomer, moving an observatory is not a common difficulty. However, B. Topham, 105 Regent St., West Toronto 9, Ontario, Canada, moved a second-hand one by truck across Toronto. It measured 10'6" in height an 10'3" in diameter and appears to have proved about as difficult to transport as an armful of eels. First, it had to be hoisted in two parts over a 10' fence and deposited on the truck. Next, before it was scarcely started, it encountered two houses bordering a driveway, which gave a space only 9' wide. This impossibility was surmounted and then came an underpass which proved to have just 2" too little head room. To beat this hazard the air was let out of the truck tires. Arriving at its destination the observatory could not be set in place as shown in Figure 4 until the sloping roof of a wing of the residence was removed and a flat roof substituted. Topham had heard so much about heat insulation, he says, that he packed the ceiling timbers beneath with "rock wool," then laid his observatory floor as a separate entity upon the roof beneath. Then with a chain block attached to a scaffold, he pulled the observatory up-another penthouse type-and there it sits-permanently he hopes, after all the adventures mentioned Perhaps it would have been easier to move the house to the observatory, but hindsight is usually easier than foresight. The dome is rotated by means of a gear working on complete inner circle of Link Belt chain. 1/8 h.p. motor does the revolving.

SOMEWHERE in earth there is a Dr. Frank Welcher who built the dome shown in Figure 5. On the back of the photograph he sent are the statements that the dome is electrically revolved and houses 6" Newtonian, but the address does not appear. (A great many persons put their addresses only on the outside of the envelop containing their communications, but in large offices incoming mail is opened by machine and only the contents are distributed by clerks to various desks. We occasionally receive an item which, because it bears no address, cannot be acknowledged. If we failed to answer your letter, that may be the explanation.)

ITS surroundings add to the attractiveness of the observatory shown in Figure 6, made by Henry E. Obermanns, 401 Hammermill Road, Erie Pa., which he describes as follows: "It is 11' outside diameter and 12' total height. The dome rotates on old roller skates, with individual skate wheels to take up the side play. The shutter is in two sections, rolling back on the other half of the roof instead of opening sidewise. Thus I can expose the apex of the roof. The slot width is 24". The telescope is mounted on a concrete post and base weighing two tons, and is steady notwithstanding the presence of a paper mill and railroad within one block. The cost was about $100 for materials (concrete, wood, 26-gage sheet metal for roof)."

BRIEF description and photographs of an observatory operated by two Jamestown, N. Y., amateurs who are said to be too modest to blow their own horn, is sent us by Leon Laskaris of Warren, Pa. Figure 7 shows the exterior of the dome and Figure 8 the interior. Bert Hansen, 530 Stowe St., and Marshall Hedstrom, 519 Stowe St., both of Jamestown, are the two. The observatory is that of the Jamestown Astronomers' Guild which has about 25 members, but the local public has the use of it two nights a week. "The aforementioned pair of hardworking Swedes," Laskaris writes, "made the 10" telescope." Microscopic examination of the original photographs of the above seems to indicate a metal roof with seams both in side and outside. The porthole in the door is interesting, and this might be a good way to dispose of astigmatized disks of glass.

THE dome in Figure 9 was made by Harold W. and Lawrence A. Cox, 47 Upper Green, Mitcham, Surrey, England. "It is 10' in diameter," Harold Cox writes, "and is built of ash hoops, slats and canvas. The opening, when the doors are fully pushed back, is 66" wide. In the picture the doors are shown half open. We had this opening made this width owing to the spread of our camera and telescope, and if you know of anyone who is looking for fun, get him to make a dome with an opening more than half the total diameter. With such wide doors we had to make them curved in both directions, for the sake of appearance, and we also had to fit special outriggers to carry the run-off track." The illustration is dark in the lower parts but close study of the original photograph with a magnifier shows, first, the lattices which are seen in front: this is apparently a fence and gate well outside the observatory building with a walk between it and the building Next, beyond this opened gate is the low hinged door to the observatory proper and, as the dome ring above it is apparently not cut, the users evidently duck under. The 'scope mounted inside is the 12" that was shown in these columns last month.

IN Milwaukee, at 807 East 1 Otjen St., lives a man named Walter Houston who sends the photograph shown in Figure 10. Minikani Observatory is the property, evidently, of the Milwaukee Y.M.C.A. Houston omits to say whether he built it or not. Let's assume that he did, but was too modest to claim credit. He writes: "Dome 13' diameter: covered with 28-gage iron. Dome frame of 3/4" pipe bent to curve; wood strips steamed to fit pipe and held with pipe clamps; iron nailed to wood strips. Wooden ring at bottom built of two layers, 16 blocks to a layer; Pipe fastened to this ring with floor flanges. Building octagonal; 10" beveled siding; eight 6r posts set in concrete; 2" x 6" sill on top; stone foundation for looks alone. Horizontal strip of 18-gage iron around dome ring and extending 5" below. Rotation afforded by roller-skate assemblies. Two sets bolted to 3~ angle iron, one for vertical thrust and one for horizontal thrust, make up an assembly. Vertical thrust against lower surface of dome ring, horizontal thrust against lower portion of the aforementioned horizontal strip of iron. Eight assemblies support dome. They are fastened to sill on top of posts.

"Floor 2' off ground. Shutters operate conveniently; rollers in angle iron on bottom; barn door hanger system on top. Cost of observatory, a little over $50. Instrument, l0" reflector; reaches 15.4 magnitude on the Harvard scale. Outside, 4" Harvard refractor; 4" f/16 reflector by George Knott (13 years old, the boy)."

FROM Fred Shunk, 923 Birch St., Scranton, Pa., we have the following communication. "You have repeatedly called attention to the necessity of designing rigid, telescope mountings. Here is one mounting you cannot criticize on that score (Figure 11). It was devised after long and bitter experience with the usual flimsy type, and was meant to be absolutely rigid-and is; yet, in your own words, it still is none too stable.

His photograph shows our 6", short-focus Newtonian, driven by a concealed Diesel engine. Partly sincerely yours " Commenting on this picture, R. W. Porter says, ''I couldn't drive the idea home better myself." But we still think the tube a shade too flexible-though if used as an RFT and held in the arms, this might not matter so much.

FROM C. A. S. Howlett, 127 Lawnside Ave., Collingswood, N. J., we have the descriptive outline of a "proposed non-stop round trip to the moon," with drawings, and with it the request that we mention it here. It turns out that Mr. Howlett, who gives illustrated talks to "resort hotels, women's clubs, student assemblies, parent teacher associations and technical organizations" (thus saith the circular he sends) holds that the earth is a hollow sphere with the moon at the center, and he proposes an 8000-mile "stratosphere" flight encircling the moon and back to earth. In his lectures he will discuss the question of establishment of right of ownership of the moon, to increase our nation's public domain and provide fat profit for the promoters of such a trip. He suggests that the moon may be surcharged with valuable minerals. Here is a chance for the overworked secretaries of amateur astronomical clubs to date up a lecture that would, no doubt, provide considerable in interest before the evening was over, especially if discussion followed the lecture! With a good telescope, on this system, it might to be quite easy to watch the war in China, just across on the opposite side of the earth.

TWO items swept up in our reading: "Emery consists of minute crystals of naturally fused aluminum oxide held together by a matrix consisting largely of iron oxide."-D. H. Killeffer, "Sandpaper Grows Up," in Industrial and Engineering Chemistry, August, 1937. "On a clear still night the temperature trace from sunset to sunrise approximates very closely to a parabola."-Prof. D. Brunt in Journal of Geography (London).

THIS month we rechristen this department with a composite name. There has been no single word that would describe the telescope making hobby. The word "optics" is broader and, moreover, persons not scientifically minded usually accept this word in the special connotation of eyeglass optics. We wish some reader would cook up a brand new word that would connote the real McKay-the tenth-of-a-fringe kind of optics. (This kind superfluous in eye work.)

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