The history of the modern computing machine goes back to Leibniz and Pascal.
Indeed, the general idea of a computing machine is nothing but a mechanization
of Leibniz’s calculus ratiocinator. Norbert Weiner
In 1623 a German Lutheran minister, Wilhelm Schickard, developed the first mechanical calculator to assist in his astronomical studies. He wrote to Johannes Kepler, a German mathematician, announcing his discovery of a mechanical way to add, subtract, multiply and divide.
It all sounded good but his next note to Kepler reported that it had been destroyed in a fire. Although this sounds a little like ‘my dog ate my homework’, notes and sketches show that the device was real. Schickard died of the bubonic plague in 1635 at the age of forty-three years.
Blaise Pascal designed a mechanical calculator to help his father, a taxman who was a moveable stone type of abacus for his work. He completed the Pascaline in 1645 when just twenty-two years old.
Pascal won royal patronage for his development together with exclusive rights to make and sell calculators in France. The calculator’s high price versus the then cost of labour resulted in no great success. Only around fifty Pascalines were made, some are still in existence.
Samuel Morland served Oliver Cromwell as a diplomat then later became a spy assisting in the restoration of the monarchy. He developed an adding machine that worked in pounds, shillings and pence, and then in 1666 designed a very early multiplying machine.
Gottfried Wilhelm Leibniz entered the calculating business in 1686. He had developed a system of differential and integral calculus and was the first to present the binary system. Apparently inspired by a pedometer, his first machine was built by 1694 and the second by 1720. It looked similar to today’s car mile counter or odometer and used repeated additions or subtractions to multiply or divide; thus it was called a ‘stepped reckoner’.
1727 Anton Braun from Germany developed a calculator which he presented to the Holy Roman Emperor Karl VI. He was appointed as the court’s instrument-maker but sadly died the following year and his designs with him.
1774 Philipp-Matthaus Hahn, a German priest, produced calculating machines accurate to twelve digits, but it was left to Charles Xavier Thomas de Colmar, a 19th century French inventor, to design, patent and manufacture the first commercially successful mechanical calculator in 1820.
1842 Poland, Izrael Abraham Staffel developed a calculator to rave reviews from the Russian Academy of Sciences and for which the Tsar awarded him 1,500 silver roubles.
Frank Stephen Baldwin reduced the complexity of the earlier systems. The Baldwin Arithmometer was patented in 1875. He received support from Jay R Monroe and together they borrowed funds to found Monroe Calculator.
William Seward Burroughs designed an adding machine to print out each entry and the final sum. Patented in 1885, it became the foundation for the Burroughs Adding Machine Company.
Austrian Curt Herzstark designed the first pocket calculator, patented in 1938. When he was sent to a Buchenwald concentration camp in 1943, the camp’s production scheduling manager wanted the calculator for his own purposes and suggested it as an ideal gift for the Führer. He encouraged Herzstark to complete his work; clearly while it was unfinished he kept his life!
The Curta pocket calculator was produced in Liechtenstein and remained popular until the 1970s. Its precision and robust, compact design saw it used in car rallies until the 1980s.