<P>... it is beneath the dignity of excellent men to waste their time in calculation when any peasant could do the work just as accurately with the aid of a machine . </P> <P> The step reckoner (or stepped reckoner) was a digital mechanical calculator invented by the German mathematician Gottfried Wilhelm Leibniz around 1672 and completed in 1694 . The name comes from the translation of the German term for its operating mechanism, Staffelwalze, meaning' stepped drum' . It was the first calculator that could perform all four arithmetic operations . </P> <P> Its intricate precision gearwork, however, was somewhat beyond the fabrication technology of the time; mechanical problems, in addition to a design flaw in the carry mechanism, prevented the machines from working reliably . </P>

Who devised the calculator known as the step reckoner