About 2500 years ago, an apparatus of stringed beads called the abacus was created to substitute for reliance on human memory when adding and subtracting.  It is still used in parts of East Asia today.  In 1617, John Napier, the Scottish mathematician who developed logarithms, invented an instrument of square “bones” on a set of rods that gave users the ability to multiply numbers.  Napier’s Bones was used widely in Europe into the mid-twentieth century. 

The seventeenth century saw three mathematicians each invent a machine for performing mathematical computations.  In 1623, Wilhelm Schickard of Germany constructed the first adding machine, the Calculating Clock, which used dented wheels to add or subtract up to six figures.  It did not become well known because the model was destroyed in a fire, and Schickard died of Bubonic Plague in 1630.  In 1643, Blaise Pascal of France built an adding machine with notched dials in a rectangular box to help his father, a tax collector, compute long series of numbers.  The Pascaline garnered quite a bit of attention, but less than 15 were purchased because it was too expensive and difficult to use.  In 1674, Gottfried von Leibniz, co-developer of differential calculus, adapted the principles of a pedometer (step-counting device) to a machine that could add, subtract, multiply, and divide.  The key parts of his Stepped Reckoner included a cylinder with teeth, wheels, and a crank.  Only two prototypes were made.  Several other inventors built calculating machines in the eighteenth century, but the instrument remained primarily a novelty until the nineteenth century.

In 1820, Charles Xavier Thomas de Colmar of France invented the first practical calculator, based on Leibniz’s principles, which performed the four basic functions of addition, subtraction, multiplication, and division.  Nearly 1500 Thomas Arithmometers were sold over the next 110 years.  An item in Harper’s Weekly “Notes on the Arts and Sciences” column of February 14, 1857, reported that Thomas had recently made improvements to his calculating machine.  The piece discussed the complicated computations the device could perform and praised its ease of use.

1) February 14, 1857, p. 111, col. 1-2
news item, calculator (“arithmometer”)

“Calculator.”  The Columbia Encyclopedia.   www.bartleby.com/65/ca/calculat.html

Redin, James.  “A Brief History of Mechanical Calculators.”  www.dotpoint.com/xnumber/mechanical1.htm