Title

Prestolog Profitmeter and Discount Calculator

Creation Date

circa 1950

Description

Round slide chart "Prestolog Profitmeter and discount calculator.  This instrument computes accurately percent of profit on selling price."  Chart iteslf is made of thin, white plastic (two concentric circles) with black printing.  Outer circle numbers from 100-990 (in fives and tens) and the inner, rotating circle, has an arrow and percentage of profit values from 1% to 89%.  Manufactured by W. A. Kempenich.
It is used to calculate the profit that can be made from sales of quantities of produce and other calculations such as the percentage loss.