A missing link in tech history - San Jose Mercury News tells the story of the construction of the "Babbage Difference Engine", which was designed but never built by 19th century inventor Charles Babbage. This is truly an engineering marvel. Frankly, I'm amazed that it works! Here's a video showing some details of this mechanical masterpiece in operation. I certainly want to head over to Computer History Museum in Mountain View to check it out.
While we're on the subject of history, here are other good resources to check out: