Allbrit Pole Wagon Polar Planimeter by Stanley

This Planimeter is a Polar type integrating machine that was made in England to calculate the area of closed irregular shapes. The pole wagon was used to enable mean readings to be taken from continuous recording charts. The wagon contains five parts: 1) a pole weight with steel pin that acts as a steady pivot. 2) A heavy iron wagon with two big wheels. 3) A sliding tracer arm with a pointer and handle. 4) A carriage with measuring wheels. 5) A magnifying glass and calibration bar. The pole weight or the wagon is connected via a hinge to the carriage. The wagon causes the carriage to always move in a straight horizontal direction. Moving the tracer pointer along the borders of the shape will cause the carriage wheel to rotate. The net roll of the wheel is proportional to the area of the shape and can be read from the calibrated scale. The Planimeter is probably new and is numbered 22851. It comes with its original leather covered box, a magnifying glass and a pole weight arm. A calibration table is glued to the bottom. Excess shipping weight applies.