American Scientist

To the Editors:

I have just seen Daniel Silver’s article in the September–October issue of American Scientist (“Slicing a Cone for Art and Science”) and thought you might be interested in this recent use of a tilted truncated cone at the Royal Observatory Greenwich (shown below). The cone is illustrated halfway down the page at http://www.ast.cam.ac.uk/~catchpol/.

I was asked to think of a design for enclosing our new planetarium. I gave my idea to our architects and was rather amused to see that their first plan showed an egg shape. Having read your article, I see they had a fine precedent in Durer.

I had a lot of fun showing how my design changed with latitude, from a dull cylinder at the pole to something like a strange elongated upturned boat near the equator.

Robin Catchpole
Institute of Astronomy
Cambridge University