[NetBehaviour] Building a 5-ton mechanical calculator... from 19th-century plans.

[marc garrett]

Building a 5-ton mechanical calculator... from 19th-century plans.


Charles Babbage's Difference Engine No. 2 automated repetitive calculations
By John Cox , Network World.

Starting in May, many will have the opportunity to see for themselves 
how they did computing the old-fashioned way: with lots of gears, a big 
crank and some muscle.

The Computer History Museum, in Mountain View, Calif., will unveil a new 
construction, the first in the United States, of the 19th century 
British mathematician Charles Babbage’s Difference Engine No. 2, an 
improved version of his earlier mechanical digital calculator.

Babbage finalized the design in the late 1840’s but it was not built 
during his lifetime, or for a long time afterward. Finally, in the late 
1980’s, London’s Science Museum launched the first and until now only 
full-blown construction project, based on Babbage’s original detailed 
drawings, and in 1991 unveiled the completed calculator, 11 feet long, 7 
feet high, with 8,000 parts in bronze, cast iron and steel, weighing 
about 3 tons.

In operation, it looks rather like an industrial version of a street 
organ. (link to image - http://tinyurl.com/4wabep )

more of the article...
http://www.networkworld.com/news/2008/041108-difference-engine.html