Wilhelm Schickard is holding a hand planetarium (or orrery) of his own invention. It was painted in 1632, 8 years after his last calculating clock drawing.
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 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.[1][2]
Hammer asserted that because these letters had been lost for three hundred years, Blaise Pascal had been called[3] and celebrated as[4] the inventor of the mechanical calculator in error during all this time.
After careful examination it was found that Schickard's drawings had been published at least once per century starting from 1718,[5] that his machine was not complete and required additional wheels and springs[6] and that it was designed around a single tooth carry mechanism that didn't work properly when used in calculating clocks.[7][8]
Schickard's machine was the first of several designs of direct entry calculating machines in the 17th century (including the designs of Blaise Pascal, Tito Burattini, Samuel Morland and René Grillet).[9] The Schickard machine was particularly notable for its integration of an ingenious system of rotated Napier's rods for multiplication with a first known design for an adding machine, operated by rotating knobs for input, and with a register of rotated numbers showing in windows for output. Taton has argued that Schickard's work had no impact on the development of mechanical calculators.[10] However, whilst there can be debate about what constitutes a "mechanical calculator" later devices, such as Moreland's multiplying and adding instruments when used together, Caspar Schott's Cistula, René Grillet's machine arithmétique, and Claude Perrault's rhabdologique at the end of the century, and later, the Bamberger Omega developed in the early 20th century, certainly followed the same path pioneered by Schickard with his ground breaking combination of a form of Napier's rods and adding machine designed to assist multiplication.[11]
Schickard has been called "the father of the computer age".[12]
- ^ Jean Marguin p. 48 (1994)
- ^ "A Brief History of Computing".
- ^ "[...] but it was not until 1642 that Blaise Pascal gave us the first mechanical calculating machine in the sense that the term is used today." Howard Aiken, proposed automatic calculating machine, presented to IBM in 1937
- ^ "Pascal's invention of the calculating machine, just three hundred years ago, was made while he was a youth of nineteen. He was spurred to it by seeing the burden of arithmetical labor involved in his father's official work as supervisor of taxes at Rouen. He conceived the idea of doing the work mechanically, and developed a design appropriate for this purpose ; showing herein the same combination of pure science and mechanical genius that characterized his whole life. But it was one thing to conceive and design the machine, and another to get it made and put into use. Here were needed those practical gifts that he displayed later in his inventions..." Magazine Nature, Prof. S. Chapman, Pascal tercentenary celebration, London, (1942)
- ^ History of computers The calculating clock of Wilhelm Schickard. Retrieved January 31, 2012
- ^ Michael Williams, p.122 (1997)
- ^ Michael Williams, p.124,128 (1997)
- ^ Single tooth carry mechanisms worked well in pedometers of the 16th century and were still used in mechanical odometers and gas meters during the 20th century.
- ^ Please see Mechanical calculator#Calculating clocks
- ^ René Taton, p. 81 (1969)
- ^ see for example discussion of true multiplying machines in http://things-that-count.net
- ^ "Wilhelm Schickard, father of the computer age".