Designed on paper by English inventor and mathematician Charles Babbage (pictured here with his creation) and built to his specifications, it is on loan for one year from former Microsoft (MSFT) tech guru Nathan Myhrvold.

(Myhrvold will be a speaker at our sixth edition of D: All Things Digital, taking place in exactly two weeks.)

Babbage was one of the great stories of the early computing age, a man who intricately designed one of the first automatic computing engines to battle the inaccuracies endemic in figures calculated by hand.

As the overview of this video relates: “Engineering, astronomy, construction, finance, banking and insurance depended on printed tables for calculation. Ships navigating by the stars relied on printed tables to find their position at sea. The stakes were high. Capital and life were thought to be at risk … it was not only the grindingly tedious labor of verifying a sea of figures that exasperated Babbage, but their daunting unreliability.”

Despite his laborious and detailed designs, though, Babbage never actually built his creation.

But other geeks took up the task and there are two now, both called Difference Engine No. 2, one in London and one now at the museum. Each has 8,000 parts, weighs five tons and measures 11 feet long and seven feet high.

Check out the video: