You're talking about a knife froe, Scott. Like as not, a necessary tool
for sash makers and a lot of furniture makers back in the day for making
the pins that held just about everything. Then it was a common enough
bench tool. I forget where I first saw one in use (maybe on The
Woodwright's Shop), but take a block of wood, say two or three inches
deep. Tie a string around it, lay out a grid. Then whip out your knife
froe and split out a whole bunch of stock for pins. Nifty, I thought,
but I kept using a chisel to make the occasional pin. Then came
coopering demos. Needed a bunch of 2, 2 1/2 inch dowels to make up the
heads. So I found and bought a 19th Century English knife froe. Made
by the dozens in Sheffield.
Mine's much prettier, but figure 7 in this article shows 3 examples;
Mike in Woodland.