Blaise Pascal is credited with designing one of the earliest forms of a calculating machine. In 1642 he invented a mechanical calculator that could perform addition and subtraction. Its operation is somewhat similar to the Lightning Mechanical Calculator shown below..
A notable early hand-cranked mechanical calculator was the Odhner. The history of Odhner calculators goes as far back as 1875 when Willgodt Odhner started producing calculators in Saint Petersburg, Russia. The Curta, invented by Curt Herzstark, an Austrian engineer a the time of WW2 was a major breakthrough for surveyors as it was small and light enough to carry in the field.
The Society has a number of manual calculators in its collection.
Calculator, Odhner
Calculator, Brunsviga
Calculator, Curta Type 1
Calculator, Curta Type II
Calculator, Facit
Calculator, Lightning