Charles Babbage
1792-1871

Babbage was born in England. After
reinventing the difference engine, he began a government-funded project to
build one by constructing a 6-digit calculator using gear technology
similar to that planned for the difference engine. Babbageand Joseph Clementproduced a
prototype segment of his difference engine, which operated on 6-digit numbers
and 2nd-order differences (i.e. can tabulate quadratic polynomials).
The complete engine, which would be room-sized, was
planned to be able to operate both on 6th-order differences with numbers of
about 20 digits, and on 3rd-order differences with numbers of 30 digits.
Each
addition would be done in two phases, the second one taking care of any carries
generated in the first. The output digits would be punched into a soft metal
plate, from which a plate for a printing press could be made. But there were
various difficulties, and no more than a prototype piece was ever assembled.