This section spans from the appearance of the abacus in China and Egypt, around 500 B.C., to the invention of the Difference Engine by Charles Babbage, in 1822. The development of the logarithmic system by Charles Napier, led to advances in calculators. By converting multiplication and division to addition and subtraction, a number of machines (including the slide rule) could perform these operations. Babbage pushed the limits of engineering when he designed and built his Difference Engine, based upon these principles.
