On Rob H's blog he posted a pic of "pins and feathers" used to split rocks.
I did my disertation on granite, so it caught my eye. IDAGS and found this:
The guy splits a 26,000 lb chunk of granite with a 2 lb sledge in an hour. Amazing.
See more in ABPW.
------------------------------------------- SFWIW, there is/was a granite quarry on the west side of Kelleys Island, one of the Lake Erie Islands, located in the western end of Lake Erie.
Every fall they would drill a line of holes in the granite, then fill the holes with water and wait for winter to do it's work by freezing the water in the holes and splitting the granite.
Water expands 1.04% by volume when it freezes and forms ice.
Does sound like much, but it was enough to split the granite to be quarried during the following season.
Lew
Another, similar, technique is to fill the holes with dry, wooden, pegs. Add water.
For the musically inclined - listen to each strike he makes on the wedges, especially the light "practice" strikes. Each makes a different "note".
Not quite as straight as he'd have liked, eh? That's probably less of a problem for foundation rocks than if the stone was being cut for thin countertops. I wonder if he turned it over and tried to straighten the left piece...
That's how he can tell the pressure, by sound. Similarly, mechanics judge the flexing of the wrench/extension/socket/bolt to know the proper torque by "feel".
The easy way:
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