On an unrelated search, I discovered that Arthur Leonard’s treatise The Yolo Reflector had been scanned and made available, including translating all the mathematical formulas into MathML. A very nice job! I have copy of the dead tree version that was mailed to me by Leonard, and it’s good to see this nifty work get wider distribution.

For those of you who may not have heard of them before, a Yolo telescope has two concave mirrors which are tilted, and thereby yield a telescope which is unobstructed. Normally, this would not work very well, as the astigmatism of tilting each mirror would add, but Leonard experimented with warping mirrors into astigmatic figures by use of a warping harness: a mechanical aparatus that bends the secondary mirror into a potato chip like shape (not visibly, but detectably at the eyepiece).

I hadn’t looked at atmsite.org in quite some time. There is an impressive array of articles contributed. I’ll be back again.