Cool spread of technology - from 1880 to 1976

I remember starting in 1979 at the insurance agency where the copier, made by 3-M, was basically a lightbox, where you took the original document, placed it between specially coated paper and a pink colored onionskin type paper, placed it onionskin down on a powerful light, exposed it for 60 seconds, then removed the original, placed the onionskin on top of the coated paper and ran it through a heat roller. Making copies was excruciatingly boring, but quite a step up from typing waxed mimeos and running the rolling mimeo machine. Ain't technology grand?