Babbage's Analytical Engine. A 'mill', or part, of the Analytical Engine designed by Charles Babbage (1791-1871). This was completed in 1910 by Babbage's son. The Analytical Engine was a development of Babbage's earlier Difference Engine. Both were designed as mechanical calculators, originally to help with work in numerical problems in the calculus. Both machines were left unfinished at the time of Babbage's death. The principles established by the concept of these machines, however, are fundamental in computing and are applied today.