On February 9th 1997, the late Professor Donald Coxeter of the University of Toronto celebrated his 90th Birthday. I was delighted that through the generosity of Robert A. Hefner III and Damon de Laszlo, the Fields Institute for Research in Mathematical Sciences placed my Symbolic Sculpture INTUITION outside their building to mark the day. (ADDED LATER: See the bottom of this page for links to obituaries for Professor Coxeter)

When I met Donald he told me about a 'geometric progression' that he had discovered, where spheres were 'mutually tangent' (see Coxeter on 'Firmament'). He asked me if I thought it would be possible to use his findings in a sculpture, and explained that the radii of the spheres are, if the unit is a decimetre, 1.5cm, 2.8cm, 5.3cm, 10cm, 18.8cm, 35.5cm, 66.8cm.

I could use only the first five spheres as numbers 6 and 7 in the sequence are too big to handle. I had the 5 spheres spun by a wood turner, and only when I put the jigsaw puzzle together was I able to see the miracle that Donald had perceived through his mathematical vision.

I mounted the spheres on a vertical rod capped by a plane set at 23.5 degrees to the horizontal plane, and used an Andalusian Tile as a base. I had used the same tile pattern to create both MUSIC OF THE SPHERES, and PROMETHEUS' HEARTH.

I called the sculpture FIRMAMENT because it reminds me of the marvellous 19th century working models of the Solar System that fascinated me as a child in the London Science Museum. I didn't understand what I was looking at then, just as I don't understand Donald Coxeter's mathematics now. What I do understand is that the Universe is a Miracle, Man is a Miracle, and that this kind of Mathematics is part of the Miracle.

Donald Coxeter's 90th birthday was on February 9, 1997, and FIRMAMENT was given to him as a birthday present from John Robinson by Ronnie Brown at the Fields Institute. The top sphere comes apart into two halves and now contains Donald's letter to John describing the mathematics of the sculpture. Later, INTUITION was unveiled outside the Institute to mark the occasion. Sadly, Donald Coxeter passed away aged 96 on 31st March 2003 in Toronto, Canada, the city he had made his home and workplace for 67 years. An account of his distinguished and influential career, and links to various Obituaries, can  be found on the St Andrews web pages : http://www-groups.mcs.st-and.ac.uk/~history/Mathematicians/Coxeter.html