The Benton Tally Register is a manual counter that was in production from 1879 until the 1960s, and in all that time there were virtually no changes to its design. In about 1907 the 4-digit version was introduced, which is the one I demonstrate here.
For more information about this and other machines in my collection, please visit my website:
www.jaapsch.net/mechcalc/
0:00 Introduction
0:46 History
1:50 Resetting
2:23 Opening case
2:31 Mechanism
4:36 Outro