The Babbage Engine
" ... as Babbage refined the mechanisms of the Analytical Engine he saw how he could simplify the design of the Difference Engine. Between 1847 and 1849 he designed a new engine, Difference Engine No. 2. The new design benefited from many of the techniques developed for the more demanding Analytical Engine.
The new design was elegant and efficient requiring one third the number of parts of Difference Engine No. 1 for greater computing power. With 8,000 parts, the Engine would weigh five tons and measure eleven feet long and seven feet high ..."