Keuffel Esser Co. Polyphase slide rule tool Science Engineer Medicin 30's Calculating tool
Era: Produced around 1882 to the mid-20th century.
Type: Duplex slide rule featuring logarithmic scales for multiplication, division, roots, and trigonometry.
Collector Status: Considered a rare and highly collectible mathematical instrument
selling as pictured.
more than welcome to pick up at shop in butler pa & save shipping.
022226 cg