I heard the guy running that project on TWiT. Apparently Babbage was
building the original machine to automate figuring out logarithm tables for
engineering books at the time. It was all done by hand back then, and I
guess there were a lot of errors. That's what the difference engine was for.
Then he thought about adding feedback to the difference engine, and the
first modern computer design was born (the analytical engine, which is what
this project wants to build.)
Interesting stuff, Babbage was *way* ahead of his time.