Figure 1 shows one of this legion, Henry Paul, 119 North Broad St., Norwich, N. Y., with a home-made tripod and mainly machined mounting carrying a purchased telescope and camera. Figure 2 shows interesting details of the mounting. Paul is a chemical engineer, with a doctorate in nutrition from Cornell, and is director of a vitamin laboratory for a pharmical house. Shop work represents his relaxation, or escape. His cellar shop is well equipped, though not over-equipped, with machine tools. There are thousands more of the same type of amateur mechanic in Yankeedom-more or less born tool-minded.

The telescope is an old 3 1/2" refractor by the forever famous Alvan Clarke. Paul states: "I have never seen a better objective. It is perfect. It gives perfect diffraction pattern and spurious disks." Paul has also made objective lenses.

The stubby camera is a Zeiss and has a 2 1/2" aperture Sonnar lens of 7" f.1 It covers a 14° field and cost $450, which is a lot of simoleons for an amateur astronomer.

The tripod weighs 35 pounds and is solid brass. It just fits a car crosswise, and, at home, a 4" pipe in a ton of concrete on bed rock.

Commenting on the mounting Paul writes: "It has a ball-bearing polar axis and main worm with friction slip-ring to hour circle. The second worm is jeweled. Reduction is 235:1, plus 22:1, to a regular 2-watt, 3.6 rpm Telechron house clock motor as sold by the thousands. This gives one revolution in 1436.11 minutes, which is plenty close to the sidereal day. If others wish to use this small motor, they should use a ball-bearing polar axis, install 15,000-ohm, 1-watt radio resistor in its housing to keep the motor warm, and mount it not closer than 1" from any large iron or steel object, as this upsets the synchronization.

"The trailer hitch, ball-and-socket mounting for the camera is handy. I have found Eastman Spectrographic Plates No. 103aE, extremely fast, particularly for dim objects of broad expanse, and very red-sensitive," Paul continues. "Used with a gelatin No. 12 (minus blue) filter, moonlight fog and sky fog can almost be eliminated with only a 50 percent increase in exposure. 9 For direct exposure on the Moon at focus I use 35mm Eastman miniature microfilm (good for 20X enlargement) and develop twice normal in D-76. This gives correct contrast. Exposure varies from 1/10 to 1/50 second at f/8, depending on phase of Moon. Eastman microfilm has a resolving power of 135 lines per mm, against about 50 for most films, and the high contrast is perfect for lunar work. In a pinch, regular high-speed press plates could be substituted for the spectrographic plates."

Paul sends no data on Figure 2. The photographs practically explain themselves and the detail is well worth close study.

Paul submitted some beautiful stellar photographs enlarged to 6" diameter from the 1" diameter originals, but no attempt is made to reproduce them here, for the same reason that has excluded many others kindly sent to this department: The half-tone process degrades them all to the same low level, the good ones, the indifferent ones, and the bad ones alike. The chances are, however, that a capable wangler could wangle photoprints from Paul, if he could exchange some similar work of his own for them.

This worker was a member of Scientific American's famous Amateur Roof Prism Gang. Too busy with his regular vocation to go into actual production, he nevertheless proved up his ability to make a high-grade roof prism, and then made a limited number in order to be sure he could do it every time. These tested up very well by others. To ex roof-prism makers the easier mirror work is going to seem like duck soup after the war. They'll be a kind of royalty of the hobby fraternity.

ECCLESIASTICUS is one of the apocrypha and in the first verse of the thirteenth chapter it says: "He that toucheth pitch shall be defiled." (See "A.T.M.," page 359). Quite obviously the author or authors of Eeclesiasticus must have been trying to make a telescope.

Here is a contribution by Dr. D. Everett Taylor, 191 Prospect St., Willimantic, Conn., who has touched pitch and been duly defiled, as have we all in our time.

"Channeling a pitch lap is one of the headaches of telescoptics. Cutting shallow channels in a revolving lap, using the point of a pen-knife, is simple. Reasonably simple also is molding the channels in a large lap with the aid of a rubber mat. On the other hand, rolling or melting in the channels on a pitch lap already formed to curve distorts the pitch surface. Cutting pitch with a knife or razor blade is tedious.

"The drill press furnishes a quick and highly satisfactory means of producing almost any desired type and size of channel. Point an old or broken twist drill with two pairs of surfaces at about 45° from the drill's axis, or point a large spike or rod with a similar, square, regular pyramid (spikes come

already pointed that general shape but @ the angles are too steep). Run the tool , thus made at 600 to 900 rpm. ,

"Draw the lap, freehand, across the rotating tool thus made, until the desired width and depth are attained. An alternative, not quite so good, is a succession of slightly overlapping holes made with the same tool.

"The quarter-inch tool will thus produce a wide variety of channels, both .1 in depth and width. For wider ones, increase its diameter."

I UNARIANS will find much of permanent value in a 76-page booklet re-print of articles by Walter H. Haas, entitled "Does Anything Ever Happen on the Moon," originally published serially in The Journal of the Royal Astronomical Society of Canada. It contains a list of lunar observers, data on observational procedure, drawings, discussion of each, on lunar colors, on lunar changes (the essential subject of the writings), and on the lunar atmosphere, also an extensive bibliography. David P. Barcroft, First National Bank Building, Madera, Calif., a member of the widespread observing group whose work is discussed, has a number of copies but only a limited number, which he therefore will be forced to allot for sale only to those who can show genuine interest. Barcroft also is a member of the Telescope Makers of Central California of which Harry R. Lytle, of Madera, is now secretary.

TEA PLATES for gauging the depth of concavity of a telescope mirror are described in "Amateur Telescope Making" by Porter on page 3, and by others on pages 310 and 344. While it is thought that a majority use the Ellison method of reflection from a wetted mirror, as described on page 78 of that book, some prefer the template, which is easier and simpler once it is made.

Figure 3 shows how Warner Williams, connected with the Culver Military Academy of Culver, Indiana, made his template. Abrasive paper was glued to the face of a motor-driven wooden disk, and the metal template strip was attached to the radius bar, pivoted at the left, far out of the picture. This bar then was worked back and forth as the motor ran.

There came, one day, to your scribe's office a large express package containing, when opened, the striking bas-relief, or plaque, made by Williams and shown in Figure. 4. This measures 3/9, x 12 1/2" x 16" and is made of cast plaster painted a delicate shade of green. William's letterhead indicates that he is a Chicago sculptor and designer. He made the bas-relief from the picture of Foucault on page 511 of "A.T.M."

This copy, cast from a negative which he has, now hangs on your scribe's office wall beside the famous framed original focogram of Mary Everest's mirror (reproduced in "Amateur Telescope Making-Advanced," page 24). Williams has also donated duplicate copies of the plaque to Russell W. Porter and to Stellafane. He states in his letter what probably few amateur telescope makers know, that Cassegrain was a sculptor.

BROKEN tool needn't mean a broken U heart. Cyril Gs Wates, Edmonton, Alberta, writes: "We are told in 'A.T.M.' what to do in case of a broken mirror, but not in the case of a broken tool. The latter is much more common because it is standard practice to immerse the tool in warm water to soften the pitch, and because tools are generally plate glass which has a high coefficient of expansion, and are therefore more likely to crack than Pyrex blanks.

"My friend, H. W. Parnall, of Foothills, Alberta, recently had the misfortune to fall down the cellar stairs while carrying a 10a plate-glass tool. (Parenthetically, Mr. Parnall has a pet dog which weighs more than he does. When Fido gets hungry, his master goes out and shoots a moose. After satisfying doggie's appetite, Parnall sends me what's left of the moose. In return, I give him bad advice on the subject of telescope making.)

"To return to our muttons, Parnall wrote and told me about his accident adding that he had mended the broken tool and finished the mirror on it. In reply to a slightly skeptical question, he said laconically: 'I wound stovepipe wire around it.'

"Now it happened that I too had cracked a plate glass tool, via the hot-water route. Taking a leaf from Parnall's book, I made a band of steel out of an old clock spring, with a screw for tightening. Having carefully cleaned the broken surfaces of the glass, I coated them with china cement, brought them into contact, put the steel band in place, tightened it, and have been using the tool ever since."

Suppliers and Organizations

The Society for Amateur Scientists
5600 Post Road, #114-341
East Greenwich, RI 02818
Phone: 1-877-527-0382 voice/fax

Internet: http://www.sas.org/

At Surplus Shed, you'll find optical components such as lenses, prisms, mirrors, beamsplitters, achromats, optical flats, lens and mirror blanks, and unique optical pieces. In addition, there are borescopes, boresights, microscopes, telescopes, aerial cameras, filters, electronic test equipment, and other optical and electronic stuff. All available at a fraction of the original cost.

SURPLUS SHED
407 U.S. Route 222
Blandon, PA 19510 USA
Phone/fax : 610-926-9226
Phone/fax toll free: 877-7SURPLUS (877-778-7758)
E-Mail: surplushed@aol.com
Web Site: http://www.SurplusShed.com