Keuffel & Esser No. 4236 Compensating Polar Planimeter With Original Hard Case

Keuffel & Esser No. 4236 Compensating Polar Planimeter With Original Hard Case  Case 9” length This German-made fixed-arm polar planimeter has a 4-1/2" metal tracer arm and an 8" pole arm welded to a cylindrical weight. A carriage on the tracer arm has a white plastic measuring wheel, vernier, and registering dial. The carriage is marked with a serial number: 10035. The pole arm is marked: K+E KEUFFEL & ESSER CO. It is also marked: MADE IN GERMANY. A rectangular metal test plate with slanted corners is marked: 10 sq. in. A wooden case covered with discolored black leather is lined with tan chamois leather, which has rust stains. A label pasted inside the lid of the case says that this is Keuffel & Esser model 4236, serial number 10035, with area of the neutral circle of 214.76 square inches. The case fits in a green cardboard box with masking tape along the edges. K&E introduced model 4236 in 1939 and began to use its K+E logo in 1949 Case and planimeter in good shape