Notes: "The Hatchet, or Pritz Type Planimeter is an elegant device that attempted to provide most of the accuracy of a polar planimeter at a small fraction of the price. It could be very cheap because in its simplest form it is one piece, with a pointer at one end of a bent steel rod and a knife edge (the “hatchet”) at the other. This particular hatchet planimeter is not one-piece, the barrel around the rod at the pointer end swivels, to provide a better handhold. I cannot determine any purpose of the barrel on the hatchet end, except to provide more weight on the knife edge, a common feature of hatchet planimeters. There is no manufacturer's name anywhere on this planimeter, and strangest of all, the knife edge is blunt, not sharp."