Luke colletti wrote: The missing sphere was made of granite, >was 7 feet in diameter and weighed 15 tons! The sphere was installed in >1912 and was removed (due to its deteriorating condition - crack(s)) in >1947.
I would have to question, from the photos, that this sphere was granite, sensu stricto. Granite is a light coloured acidic plutonic rock, and this sphere looks very dark. I also wonder why it started cracking; granite is a very resistant rock. Is there any information on just where the material for the sphere was quarried? For the past 4-5 years there has been a small market (I assume it's small) for large decorative rock spheres (granite, marble, larvikite - which has a nice iridescence in the feldspar crystals, sodalite - a delicate pale-blue colour, etc) mounted in a hollowed block of the same, and supported by a thin film of water. They are thus rotatable in all directions, and by hand no less! It's a strange feeling to change the direction of such a heavy piece by hand presure alone. I've seen them up to about 4 feet diameter (but usually smaller), but I agree, a 7 foot diameter solid sphere would pose problems. But if only for the replacement of such a large sphere of solid rock (which may be the largest anywhere?), it's surely worth doing. Peter Tandy -
