you have to split stone, feathers and irons certainly simplify
the process. For many centuries, this was the only non-explosive
method of quarrying rock until hydraulic systems were developed.
The splitting is fairly simple. Start by drilling holes along
your split line, which can be straight or curved. The holes
should be as deep as your wedges are long. The spacing between
them will vary depending on the type of stone. Place the feathers
and irons into the holes, ensuring that the feathers' ears
face the direction you want the stone to split. Firmly, but
without forcing, strike the wedges in sequence; repeat this
process until the stone splits.
By drilling several holes in a row and judiciously tapping
the irons to develop a fairly even pressure line, you can
split rocks quite accurately. With only a single hole, the
result is less predictable.