I am briefly breaking my vowed silence to share something too cool not to tell you about.
Someone actually built a
Babbage difference engine---and it works! (For those who don't know, that's one of the first computers designed by the mathematician Charles Babbage in the mid 19th century. A working prototype was never completed in his lifetime.)
This video tells you all about it---it's full of delicious geekness. Enjoy!
Thank you
Dave Kellett for the link.