Rack adding machine Serial number
4665
This is a chain drive
adding machine, manufactured in Germany circa 1910.
Numbers are entered by
using a stylus to pull each individual rack down to the
crosspiece at the bottom. The number can then be verified
before it is added, which is done by depressing the lever at
the lower right. For rapid data entry, the lever can be set
to M, and the chains automatically spring back after the
numbers are entered. Pulling the small crank,
which automatically springs back to its neutral position,
clears the result mechanism. The machine features
automatic tens-carry as well. Using the scales on the sides,
which display complementary digits, one can perform
subtraction.