Wilhelm Schickard

Who was Wilhelm Schickard?

Wilhelm Schickard was a German professor of Hebrew and Astronomy who became famous in the second part of the 20th century after Dr. Franz Hammer, a biographer of Johannes Kepler, claimed that the drawings of a calculating clock, predating the public release of Pascal's calculator by twenty years, had been discovered in two unknown letters written by Schickard to Johannes Kepler in 1623 and 1624.

Dr. Hammer asserted that because these letters had been lost for three hundred years, Blaise Pascal had been called and celebrated as the inventor of the mechanical calculator in error during all this time.

After careful examination it was found that Schikard's drawings had been published at least once per century starting from 1718, that his machine was not complete and required additional wheels and springs and that it was designed around a single tooth carry mechanism that didn't work properly when used in calculating clocks.

Schickard's machine was the first of five unsuccessful attempts of designing a direct entry calculating clock in the 17th century. Schickard's work had no impact on the development of mechanical calculators.