Calculator

This middle section consists of the accumulators which makes this a digital rather than analog calculator. Each step in the polynomial calculation is added in the long columns which consist of cylinders of digits. Each group of columns makes a register holding 31 numeric digits. There are 7 registers, meaning that polynomials up to the 7th order can be calculated.
Babbage spent a lot of effort putting interlocks into the machinery, so that it was impossible to have a partial result anywhere in the machine. Either a cylinder turned a whole digit, or it did not turn at all. If something was to cause a partial turn, the interlocks would force the machine to jam, thus alerting the operators to a fault.

Next