Pascal's Calculator

Pascal's Calculator

Blaise Pascal invented the mechanical calculator in 1642. He conceived the idea while trying to help his father who had been assigned the task of reorganizing the tax revenues of the French province of Upper Normandy; first called Arithmetic Machine, Pascal's Calculator and later Pascaline, it could add and subtract two numbers directly and multiply and divide by repetition.

Pascal went through 50 prototypes before presenting his first machine to the public in 1645. He dedicated it to Pierre Séguier, the chancellor of France at the time. He built around twenty more machines during the next decade, often improving on his original design. Nine machines have survived the centuries, most of them being on display in European museums. In 1649 a royal privilege, signed by Louis XIV of France, gave him the exclusivity of the design and manufacturing of calculating machines in France.

Pascal designed the only functional mechanical calculator in the 17th century. He succeeded because he was the only person to shrink and adapt for his purpose a lantern gear, used in turret clocks and water wheels, which was capable of resisting the strength of any operator input with very little added friction; he was also the first person to make each digit independent of the state of the others allowing for multiple carries to rapidly cascade from one digit to another regardless of the capacity of the machine.

Its introduction launched the development of mechanical calculators first in Europe and then all over the world, development which culminated, three centuries later, in the invention of the microprocessor developed for a Busicom calculator in 1971 ; the microprocessor is now at the heart of all computers and embedded systems.

The mechanical calculator industry owes a lot of its key machines and inventions to the pascaline. First Gottfried Leibniz invented his Leibniz wheels after 1671 while trying to add an automatic multiplication feature to the pascaline, then in 1820, Thomas de Colmar drew his inspiration from Pascal and Leibniz when he designed his arithmometer, the first mechanical calculator strong enough an reliable enough to be used daily in an office environment, and finally in 1885, Dorr E. Felt substituted the input wheels of the pascaline by columns of keys to invent his comptometer, the first calculator operated by keys and the first calculator to receive an all-electronic calculating engine in 1961.