Charles Babbage
In Babbage’s time numerical tables were calculated by humans called ‘computers’. At Cambridge he saw the high error rate of the people computing the tables and thus started his life’s work in trying to calculate the tables mechanically, removing all human error. He began in 1822 with what he called the difference engine, made to compute values of polynomial functions.Unlike similar efforts of the time, Babbage's difference engine was created to calculate a series of values automatically. By using the method of finite differences, it was possible to avoid the need for multiplication and division.The first difference engine needed around 25,000 parts of a combined weight of fifteen tons standing eight feet high. Although he received much funding for the project, he did not complete it. He later designed an improved version, "Difference Engine No. 2". This was not constructed at the time, but was built using his plans in 1989-1991, to 19th century tolerances, and performed its first calculation at the London Science Museum bringing back results to 31 digits, far more than the average modern pocket calculator.
