Thus does A. B. Stephens open a letter written from Negya, Chauk, Burma, where he has been drilling oil wells. He continues: "The glass is of six-inch aperture and was furnished by John Pierce of Vermont, along with the prism and eyepiece. Grinding and polishing the glass required several months, working a few minutes each day, and the figuring took another long period of time as I overshot the mark while parabolizing it and got a nice deep hole in its center. After the hole was finally removed, a comparatively short time was necessary to bring the surface to a good figure. My greatest trouble was in finding a lap to stand up in this warm climate but finally one made of tar and rosin served very well. The silvering was a complete success the first time.

"Let all those who are eager to make mirrors but do not have the ideal conditions as set forth by Ellison, take heart for, as one of the photographs shows, all of the grinding and polishing of this little mirror was done on the veranda of my bungalow, with, of course, all of the shutters closed. While the glass, no doubt, falls far short of the standard of Ellison and Porter, yet it gives a wonderful view of the heavenly bodies. Not only are the rings of Saturn sharply defined but also several of its moons; two in particular, perhaps Hyperion and Titan, with momentary pinpoint flashes of two of the closer moons.

"I leave here shortly and thereafter my address will be 816 East Mayne Street, Bellflower, California."

ALL over the world, in the most out~of~the~way places, in homes, on library tables and in the reading rooms of clubs you will find the SCIENTIFIC AMERlCAN. Here is a letter which reached us from New Zealand, written by Robert Bruce of 33 Vincent Street, Auckland:

"I have read with interest of the many ingenious astronomical telescopes made by amateurs. The humble efforts of a grocer might interest your readers. I enclose a photograph of my three-inch home-made refracting telescope. Having a 31/2-inch Drummand lathe I may have an advantage over some amateurs. The telescope and equatorial mountings are in brass and gun-metal throughout, except the declination axis, telescope cradle, and R. A. axis, which are of mild steel. As the photograph shows, the polar axis is adjustable to all latitudes. There are slow motions in R. A. and declination. The R. A. circle is divided into 11/12-degree divisions and declination circle likewise. The R. A. circle is a rebated ring which for adjustment rotates on a central rebated disk which is firmly clamped to the polar axis. The circle is read by one fixed vernier and one movable one.

"To adjust telescope to R. A. of star, first place it in the meridian position, rotate R. A. ring till desired R. A. is read off fixed vernier, then clamp ring to disk and move telescope till correct sidereal time is read by the same vernier, and there you are. Then, while the star is still in the field, put movable vernier to correct time by your watch and clamp it. For the rest of the evening, to find other stars turn telescope to meridian, adjust circle as before to desired R. A. at fixed vernier, consult watch and set telescope to read correct time of your watch from movable vernier. Thus you will be able to find your star without again calculating sidereal time."

A SIMILAR idea has been submitted by A. V. Goddard, 282 Northeast 49 Street, Portland, Oregon, whose 16-inch reflector was described in our number of last January. Though original with these workers the idea is not a new one, but is a good one, nevertheless. Here is how Goddard describes it:

"I have worked out a simple plan for using circles without the use of an expensive sidereal clock for calculations. Large observatories have used a system of three circles for calculating right ascension for years, but it is necessary to use a sidereal clock.

"You will note on the enclosed drawing three elements, A, B and C. A is a pointer fixed to the tube of a telescope. This moves on the hour circle when the telescope b moved. B is the hour circle but is movable on the polar axis, and may be locked by means of a thumb-screw. C is an ordinary vernier with zero point, fastened permanently to the mounting of the telescope. This is all the equipment necessary, except for an ordinary cheap alarm clock or a watch that will keep fair time for few hours and can easily be set.

"Here is the procedure: Look for any first magnitude star or object with a known right ascension. One near the zenith is best as this avoids refraction. Take Regulus, for example, at R. A. 10 h 4 m. Loosen the thumb-screw on the hour circle B, and revolve the circle on the polar axis until the pointer A indicates 10 h 4 m. Now lock the circle with thumb-screw. Line up the crosshairs in your finder exactly on Regulus and set your clock for the exact time indicated on your vernier C and hour circle B. The clock will now take of all difference in time for the remainder of the night. Now that the clock is set, it is a simple matter to find anything you like.

"This may sound complicated but if once tried you will be surprised at the simplicity The drawing indicates 8 o'clock as shown on your clock. The pointer A may be placed in any convenient position relative to the tube, as long as the R. A. circle B can be revolved under it. I have used this system for a long time and find it very satisfatory.

HERR SASCHA CHAGUN sends us the following note from Schwäb Hall, Schuppach Str. 1, Canstatt, Germany:

"I enclose a photograph of my telescope, which in part was made according to your book 'Amateur Telescope Making.' The mirror has a diameter of 24 centimeters and a focal length of 2.2 meters. It was polished on a paper lap, using tripoli. In as much as this method of polishing is simpler and safer than the wet process (the polish is never as perfect which, however, does not decrease the optical efficiency) I am surprised that you did not mention this method in your book. Maybe you will consider it in a later edition. I think your book is excellent and I hope it will enjoy the widest dissemination."

We cannot agree with Herr Chagun about the paper polisher or about the optical efficiency. Also, we did mention this matter in the instruction book "Amateur Telescope Making." On page 255 Professor Elihu Thomson correctly says, concerning the paper polisher, "It cannot be expected to yield the high accuracy that may be obtained with pitch." Bell, in "The Telescope," page 71, says, "Cheap lenses are commonly worked on a cloth polisher or sometimes on paper worked dry.

With care either may produce a fairly good surface, with, however, a tendency to polish out the minute hollows left by grinding rather than to cut a true surface clear down their bottoms. All first class objectives and mirrors are in fact polished on optician's pitch." For years Dr. Woolsey Blacklock of England has been using and urging the use of the paper polisher, his letters in English Mechanics being answered chiefly by

Ellison who takes the position that this kind of lap is distinctly inferior to the pitch lap, mainly because it permits of no accurate contacting and lacks the "spring" and life of pitch. We vote for pitch or HCF.

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.