When I acquired this machine one of the columns of keys was intermittently slipping. After studying it for some time, I realized the problem was that the gear was not under tension. I eventually found the spring that had slipped off and was able to re-attach it. Amazingly, the spring still had its hooked end that secures to a tiny, almost microscopic, hole on the gear. Once reattached the slipping stopped.
The next problem was that a column of numbers was not consistently carrying over the results of the adjacent column. Again it was a problem of a sort of clutch not being under tension. When I tried to reattach the spring, the end snapped off. Fortunately, I was able to uncoil the spring enough to obtain a length that could be reattached to the clutch.
Complementary subtraction is performed by adding the complement (small digit on the keytop) and preventing the carry-over through the use of the carry-over inhibitors (shown above the decimal indicators in the photo above).
Odd-numbered and even-numbered keytops were shaped differently in order to assist the operator in positioning their hands on the machine.
Clearing the result register - in order to release the register from its locked position, the lever is depressed, after which the register can be cleared by rotating the knob above.
The keystems were round with springs between the keytops and the keyplate. The keytops themselves were of the "typewriter" variety with a metal ring surrounding a celuloid inset containing the character.
Serial number 4635, with patent plate dated September 22, 1896
