2020-S $1 American Innovation CT Gerber Variable Scale First Day of Issue Gerber Variable Scale, DCAM PR70DCAM 认证号40781572, PCGS号836070

2020-S American Innovation Connecticut - Gerber Variable Scale {First Day of Issue} PR70DCAM { PCGS-4 }. Joseph Gerber, born in Austria in 1924, and following imprisonment in a Nazi labor camp at the age of 15, escaped with his mother to the United States and settled in Connecticut. While in college, he invented the Gerber Variable Scale, which many consider the most revolutionary engineering tool since the slide rule. By the 1950s, the variable scale was one of the most widely used tools for engineers and architects worldwide. Though calculators and computers have replaced it, Gerber’s scale was integral to the scientific advancements of the 20th century.