By Wilhelm Schickard – “horologium ebraeum”
Rare book wrote by W. Schickard and printed in 1675 (first edition). It’s a textbook of Hebrew divided into 24 chapters, each chapter containing material which could be learnt in an hour.
Who was Wilhelm Schickard ?
Wilhelm Schickard (22 April 1592 – 24 October 1635) 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 (along with Max Caspar) 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 springsand 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 (including the designs of Tito Burattini, Samuel Morland and René Grillet). Schickard’s work had no impact on the development of mechanical calculators.
Wilhelm Schickard died of the bubonic plague in Tübingen, on 23 or 24 October 1635. In 1651, Giovanni Riccioli named the lunar crater Schickard after him.