[VOA]

I wonder if Obama could tell you what Charles Babbage built (even if
someone else proposed it).

Difference Engine
http://en.wikipedia.org/wiki/Difference_engine

[wideminded]

I wonder if Obama could tell you what Charles Babbage built (even if someone else proposed it).

Difference Engine http://en.wikipedia.org/wiki/Difference_engine

I'm not sure that Babbage ever actually built the "Difference engine". He is famous for producing the plans for it.