A few minutes after I’d read the announcement that IBM is now shipping a five-billion-instructions-per-second processor, I noticed another story about computing that I thought you might find interesting in contrast.

Charles Babbage died in 1871, having designed but never constructed the very first programmable computer. Incomplete pieces of his Difference Engine #2 had been on display for many years in the London Science Museum. In 1991, though, the museum actually constructed a complete model of the Difference Engine, based on Babbage’s detailed plans. And what do you know? It worked.

It’s hard to overestimate the mechanical and mathematical smarts that went into this design, using materials and concepts from the 19th century. Oh, sure, it’s a billion times slower than the calculator in your drawer, it’s operated by a hand-crank, weighs 4.5 tons, and it’s not as advanced as Babbage’s later Analytical Engine. But still, it’s one sweet machine.

Three years ago, Nathan Myhrvold asked the museum to build another full-sized model for his own personal edification, and now it’s been delivered. You can read more about this magnificent device here.

(Photo credit: Daniel Terdiman/CNET News.com)