-
Old school computing
One of my favorite memories is visiting my father in his office in the 1960s (he was a civil engineer). He had a big mechanical calculator which was very impressive. He keyed in numbers then hit the button and you knew some calculating was going on by the hum and clatter of the machine. I asked him if that was the answer but he said no he had to look it up in the book (log table I assume or maybe arc tangent table), that was disappointing to me.
I found an old book of log and functions tables when we moved the office so I played with it a little bit, I did a Pythagorean calculation using common logs. Those old books were ingenious how they were setup. By the time I was done my paper was full of penciled calculations and log numbers all over it.
We have the old traverse sheets, distance, bearing, cos, sine, lat, dep, north, east. So I wondered how they multiplied those numbers. I know they had logarithmic functions but these are the natural cos etc.
Dad told me he had a Marchant calculator in the 1960s. The one I found did four functions so I guess they didn’t need to add the logs to multiply:
http://www.vintagecalculators.com/html/marchant_figurematic.html
Log in to reply.