Charles Babbage is a person I greatly admire. The Difference Engine is such an amazing thing to have invented. Back in the days when humans had to calculate by hand reams and reams of tables to allow easy and precise calculation, a machine that could generate these tables without human error would have been invaluable. Which is exactly why Mr. Babbage received tons of money to build such a device. Sadly, the original design was too cumbersome to be built. His revision, the imaginatively named Difference Engine No. 2, was never built because he became enamored, until his death, with his Analytical Engine which could be programmed with punch cards. He died in 1871.
The London Science Museum built his Difference Engine No. 2 (to the tolerances of his time) in 1991 and I saw it in action when I visited it that year. It was astounding. I stared at it for a long, long time.
Ada Lovelace, the only legitimate child of Lord Byron and quite the renaissance woman, was translating notes on the Analytical Engine from an Italian mathematician for Mr. Babbage. Appended to the notes was a method of using the machine to generate Bernoulli numbers. Many people attribute this as the first computer program. Apparently, there is some evidence that Mr. Babbage had written the algorithm and she was simply correcting an error he had made. If that is the case, then I'd say she found the first bug.