As you probably know if you've used Google at all, today is the 197'th anniversary of Ada Lovelace's birth (LEGO Ada by Dunechaser). She is referred to as the world's first computer programmer, since in 1842 she designed an algorithm to use Babbage's analytical engine to compute the Bernoulli numbers.
Babbage's difference engine was a mechanical calculating machine that pre-saged later computers. Due to technical difficulties he never actually built it in his lifetime. Here is a difference engine built in LEGO by Andrew Carol - this was a precursor to the analytical engine.