Vintage Heating Unit Slide Rule Calculator - Hoskins Chromel "A"
RARE & HARD TO FIND
Early 30's Slide Rule by Hoskins Manufacturing Company.
This is a vintage slide rule calculator for figuring out the data on a heating unit design for 100-volts, A.C. or D.C., using Hoskins - Chromel "A". We're not sure if this slide rule calculator came with a purchase of the unit or was a promo item. It has some staining and the paper is slightly warped, but you might be able to flatten it back by pressing on the flat surface with heavy weights. We really appreciate the old design details of these precise gadgets that people used to use in their daily lives to figure out mathematical formulas and percentages before there ever were any computers. Perfect for someone who collects unique slide rules & calculators.
YEAR: 1933 copyright
SIZE: 6.5" x 3.5"