Arithmometer

History

The Odhner was invented in 1874 by Swedish engineer W. T. Odhner.

The Odhner machine was a rotary, crank-operated mechanical calculator based on the pinwheel principle. His successful design became the model for many other successful calculators which followed, such as the Friden, Brunsviga, and Marchant.

He first produced the Odhner Model 1 Arithmometer around 1886. He obtained a patent on his machine in 1891.

It was later mass produced in St. Petersburg, Russia. In 1926, it sold for about $300.

Addition:

Subtraction:

Multiplication:

For example: If we are multiplying 768 x 256 then:

a) turn the dial 6 times;

b) shift the left counter right;

c) turn the dial 5 times;

d) shift the counter right;

e) turn the dial 2 times.

Division: