Greetings!
It is only in the last day or so that I have noted the discussion concerning
the stereopgraphic projection, that wonderful invention of the ancients to
solve problems involving the astronomical triangle. It took a bit of time
to find the reference in a old book from my college days, but I'd like to
add a rather pretty discussion of the proof in
David Hilbert and S. Cohn-Vossen, _Geometry and the Imagination_,
New York, 1956, Chelsea Publishing Co., a translation by P. Nemenyi of the
famous _Anschauliche Geometrie by these authors; pp. 248-59.
I just thought someone might like to check it out, too.
John
