
The 17th Century: The Invention of the First "Computers" 

The devices often considered the first "computers" in our understanding were rather calculators than the sophisticated combination of hard and software we call computers today.
In 1642 Blaise Pascal, the son of a French tax collector, developed a device to perform additions. His numerical wheel calculator was a brass rectangular box and used eight movable dials to add sums up to eight figures long. Designed to help his father with his duties, the big disadvantage of the Pascaline was its limitation to addition.
Gottfried Wilhelm von Leibniz, a German mathematician and philosopher, in 1694 improved the Pascaline by creating a machine that could also multiply. As its predecessor Leibniz's mechanical multiplier likewise worked by a system of gears and dials. Leibniz also formulated a model that may be considered the theoretical ancestor of some modern computers. In De Arte Combinatoria (1666) Leibniz argued that all reasoning, all discover, verbal or not, is reducible to an ordered combination of elements, such as numbers, words, colors, or sounds.
Further improvements in the field of early computing devices were made by Charles Xavier Thomas de Colmar, a Frenchmen. His arithometer could not only add and multiply, but perform the four basic arithmetic functions and was widely used up until the First World War.


Calculator
Calculators are machines for automatically performing arithmetical operations and certain mathematical functions. Modern calculators are descendants of a digital arithmetic machine devised by Blaise Pascal in 1642. Later in the 17th century, Gottfried Wilhelm von Leibniz created a more advanced machine, and, especially in the late 19th century, inventors produced calculating machines that were smaller and smaller and less and less laborious to use.


