The photographer sent several pictures including the following, with comments. Click on individual photos to see enlargments. The first photo is well worth enlarging - The Editor
 

Closeup #1

" I'm sending you pics I took of a chamber that is made of mostly quarried granite that was split by someone boring holes in it 18" in depth.  I think these holes were filled with water, plugged, maybe with wood, then allowed to freeze, splitting the rock.  The bore holes do not appear round, they seem to be three sided, like a triangle with rounded corners.

Closeup #2

Behind this chamber, up on a hill, there are dozens of granite boulders each with a single hole, equally deep.  The larger boulders had a larger hole ( in diameter ) than did the smaller boulders.

Single Hole in Rock

I have also seen this three sided hole bored into entrance stones to chambers but only about 3-4" deep.

Hole at Chamber Entrance

Has anyone analyzed these  borings to determine what type of tool was used ?  Boring an 18" hole in granite has to be one tough job !  I have not heard too much mentioned re: these holes, but I think there is one on the lintel stone at Calendar 2 in VT  ? "

     
View Out the Entrance to Stone Chamber, detail of bore scar.
 

Whangton Chamber. Putnam County NY