William Schickard

 

1592-1635. Schickard's "Calculating Clock" was constructed in Tuebingen Germany. This was  a 6-digit machine that could add and subtract, and indicated overflow by ringing a bell. A set of Napier's Rods (or Bones) was mounted on the machine, a memory aid facilitating multiplications. The machine and plans were lost and forgotten in the war that was going on.

The plans were finally rediscovered in 1935, only to be lost in war again, and then re-rediscovered in 1956 by the same man. The machine was reconstructed in 1960, and found to be workable. (Schickard was a friend of the astronomer Kepler.)