Pitching. Cutting etc.

Quoted text begins.I
always assumed that the name came from the way the hammer
bounces around
when you use it.
End of quote.

Thanks, George. That was my working assumption as well.
Then I started thinking of bumpers being used to texture
sawn surfaces with bumps. In your monument shop you spoke
of a clattering rig that ran several bumpers
simultaneously. Was the purpose of that rig to level
rough surfaces, or was it to create texture on a sawn
surface.

Rethinking what T&H said about stoneworkers protesting the
introduction of the bumpers because of all the work it
did, I suppose that is not cynical but simply true as a
job was being lost to a machine.