As I mentioned recently, I’m working my way through James E. Morrison’s book “The Astrolabe”: seeing so many astrolabes at the Museum of the History of Science in Oxford was good fun, but I still want to get all the maths and celestial mechanics straight in my head – I’m never really happy until I get Art and Science in some kind of balance. Curiously, I worked for a camera company (/*you know who you are*/) not so long ago where stereographic projection (as used in astrolabes) is central to its business: isn’t it strange by how little maths has changed over the millennia?
But before the astrolabe, there was a set of objects known as anaphoric clocks (as mentioned by Vitruvius, De Architectura, Book IX, Chap. 8, 8-15): the Tower of the Winds in Athens is generally believed to have had one of these. These are deceptively simple objects, comprising a wire framework top layer (known as a “spider”) to represent the hours of the day, and a backlayer containing both a stereographic projection of the night sky and a circle of peg holes marking the sun’s position as it moves through the zodiacal year. (All basically as per Morrison, “The Astrolabe”, pp. 33-34).
And now Kansas City is host to a brand new (and really quite funky) anaphoric clock, thanks to local artist Laura DeAngelis (with help from Peregrine Honig), as well as the advice and calculations of Jim “Mr Astrolabe” Morrison himself. If you happen to be in Kansas City unexpectedly (for example, if you click your heels, Dorothy), why not have a look for yourself? The anaphoric clock is in the Oppenstein Brothers Memorial Park, and I think it’s just fabulous (but I would, wouldn’t I?)
Hello! I recently went to see the Star Disk in Kansas City and put together a FB album about it. It was quiet impressive and there’s more to it than the astronomical part.
Strictly speaking, it’s not an anaphoric clock, since you have to set the time and date on it by hand yourself. You can buy planispheres that are the same thing for very little money.