I've always been fascinated by the story of Charles Babbage, who had a passionate interest in applying the tools of the industrial age to building machines that could solve problems. He completed the design for a super calculating machine, the Differential Engine, and he worked (along with Lady Ada Lovelace) on the design for the Analytic Engine, which anticipated the modern digital computer.
In his lifetime he ran through some large grants from the British Crown attempting to build the Differential Engine, but was never able to complete a working prototype. In the 1980's a curator at the London Science Museum discovered the original plans and embarked upon a project to build a Differential Engine. While modern manufacturing techniques were used, it was built to tolerances that would have been attainable in the mid-Nineteenth Century. The working machine was displayed in London starting in 1991 and I got to see it in 1992. It's a beautiful creation of gleaming bronze and steel and a remarkable intellectual and manufacturing feat.
I had no idea when we made plans to visit the Computer History Museum in Mountain View that they now have the SECOND Differential Engine model, and furthermore they demonstrate it in operation. And even better, they have completed Babbage's vision by including a printer/typesetter - the purpose of the machine was to typeset tables of mathematical results that could be used to print books and eliminate human error. The machine was commissioned by Nathan Myhrvold ex-Microsoft guru, and fortunately he agreed to show it off at the museum for a year. If you're anywhere near Mountain View between now and April, come by and take a look - and be sure to stick around to watch them operate the machine. It's a beautiful thing.