OTC Time Calculators

Time to Call?

by Robert Brand.

Graham Watts sent me these photos of OTC time calculators. Very useful even today. I have already posted one to the header images some weeks back, but Graham has sent three more plastic types all different from Mine. He also notes that there may have been at least one cardboard version of the calculators. If anyone has different versions of these, please send to me so that we can add them to the photographic collection. Continue reading