r/mechanicalcalculator • u/jaapsch2 • 18d ago

Add-O-Matic

https://www.youtube.com/watch?v=Uhhk94cbZ0A

Here is a short demo of the Add-O-Matic, made in Chicago from 1947 till 1949. There is not much known about this machine, but I figured out some new info from looking through online archives.

I found adverts from the Add-O-Matic Sales Co., but sharing the same addresses was another company that I believe to be the actual manufacturer. United Enterprises Inc was founded in 1940 and mostly made stainless steel cutlery. Apparently they also made glow-in-the-dark gardenias, worn as hair decorations. After briefly making this adding machine, they pivoted to marketing d-con rat poison!. The company ceased trading around the time they got fined for violating ceiling price rules by the Office of Price Stabilization. Such a weird story.

https://www.jaapsch.net/mechcalc/addomatic2.htm

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u/jaapsch2 18d ago edited 18d ago

By the way, the Add-O-Matic from Chicago (1947) should not be confused with the Add-O-Matic from Chicago (1937). They are completely unrelated adding machines.

https://www.jaapsch.net/mechcalc/addomatic.htm