this machine could handle the four arithmetic functions,
had a delayed carrying device, and contained the stepped
drum principle, which 150 years later was used in the
first commercially successful calculator.
As far as we know, Leibniz built two machines. He spent
years of his life improving them so they would be practical.
But, the technology of fine instrument making could not
yet reach the precision that was essential. Leibniz's
dream was unfulfilled.
The story of 18th century calculating devices is one of
experiment in which all possible changes were made to
the inventions of Pascal, Moreland and Leibniz.