On April 4, 1617, Scottish mathematician, physicist, astronomer and astrologer John Napier of Merchiston, the 8th Laird of Merchistoun passed away. John Napier is best known as the discoverer of logarithms. He was also the inventor of the so-called "Napier's bones", a kind of abacus for calculation of products and quotients of numbers. Napier also made common the use of the decimal point in arithmetic and mathematics.
On October 23, 1635, German astronomer and mathematician Wilhelm Schickard, who constructued the very first mechanical calculator, passed away. His famous calculator was able to perform additions and subtractions. For more complicated operations, it provided so-called Napier bones, named after the Scottish mathematician John Napier, who came up with the idea of logarithms. Although it is widely believed that the first mechanical calculating device was created by the French mathematician Blaise Pascal in 1642. However, that distinction actually belongs to Wilhelm Schickard.