The mechanical calculator (7h 50min, nov 18, 2018 y – 20h 53min, jul 30, 2019 y)
Description:
The mechanical calculator then invented by Thomas de Colmar in the mid-nineteenth century, and subsequent others. It was called the Arithmometer. The concept was improved with pinwheel calculators invented by Baldwin and Odhner.Added to timeline:
Date:
7h 50min, nov 18, 2018 y
20h 53min, jul 30, 2019 y
~ 8 months