How did Charles Babbage's Difference engine work?

I have never seen a good diagram, but the device was mechanical, not electrical and would probably resemble an early code machine ( used to make and decode ciphers) or possibly a mechanical (these antedated the juice variety) digital clock the possibility exists it may have used a clockwork, wind up motor, also. read out would be digital as explained, like a mechanical adding machine or the now-rare mechanical digital clocks, which were invented in Germany. I have no further information on the Babbage device, which never was, well a household appliance.