Boulder splitting question

[Jeff Spencer <jeffespencer@zzzzzzzzz>]

Splitting rock with hand tools (OK, hand tools and an electric roto-hammer)
is really cool! Playing with wedges is fun :)

Yesterday I started working on the boulder. I drilled 7 1/2" holes and used
the wedges and shims on the crack I found that wasn't too far off level. I
think the crack already went most of the way through. The shims easily
opened the crack. I then used a large pry bar to open it further. Then with
a chain I was able to use my truck to move the top out of the way. The top
was an oblong cone that at the base was about 4 feet by 7 feet and at the
thickest about 2 feet.

This left a slightly slanted fairly flat plane to work with. I'm hoping this
represents the natural splitting grain of the rock. I'd like to take another
foot off the top. I decided my 8 wedges couldn't do this since the rock is
getting bigger the deeper I go. So instead I decided to try splitting it
 from the top town in the center before attempting to take any off the top.
With 8" deep 1/2" holes across the center of the top of the rock I was able
to split it. The split really meanders, so I figure I was splitting across
the grain. I don't know how deep the split goes, I've only dug down 18"
below the new top of the rock.

Next week I plan to try to take 12" off the top with the tools I have at
hand. I'll need the grain of the rock to help me, since I'll be trying to
get a split to go through 48" rock instead of moving upward through 12" of
rock. If I had a 48" drill I'd drill all the way through before splitting,
but I don't.