THe history of early computation

A fascinating little history of early computation, best read as a narrative.

Previous attempts at effort-saving devices did not suit Blaise’s plans. He needed a machine that would add up large sums of numbers automatically, or repeatedly subtract. Napier’s Bones, created by John Napier (1550–1617) were efficient for multiplying and dividing numbers. Based on the multiplication table, they drew upon a lattice form of multiplication, and by aligning the bones, or rods, in a certain way, addition could be done instead of multiplication, and subtraction in place of division.

A calculating clock had been invented by Wilhelm Schickard in the 1620s, based on Napier’s bones. It used pinwheels to ‘carry’, and was designed to be able to add, subtract, multiply and divide. It was described in letters from Schickard to Johannes Kepler, but was never seen working. Later examination of the descriptions in the correspondence suggest that the mechanism would jam, especially if several carrying actions happened simultaneously.

Blaise opted for a simple design based on addition. The machine would be set to zero, and then the operator would use a stylus to enter an initial number by using the digits around the circumference each dial as reference points. The stylus would reach a stop bar, as the dial was turned,  just like on a rotary telephone dial.

He wanted to sell the calculators for widespread use, but they proved to be very expensive due to the intricate parts. Instead, the Pascaline was seen more as a status symbol for European nobility. Even though fewer than 20 were sold, the Pascaline was the first working automatic calculator, inspiring later inventors and mathematicians. Mechanical calculators were used around the world well into the 1970s, when electronic versions started to take over.

http://chalkdustmagazine.com/biographies/roots-blaise-pascal/