In the early days even before the cash register, store owners had to have a method of protecting their money & keeping track of their sales. They had hidden drawers attached under their counters & of course ledger books.
Someone combined these two things together & built a box with a lockable drawer & a tally roll of paper. Almost every cash register company picked this up & started building their own version.
I think National built more variations than anyone else. I have even seen a picture of a 6 drawer Autographic machine. The National factory in Germany really excelled in this.
Of course National really went out of their way to make security a big part of the machine. They had a selectable secret button system for the operator to use. The register won't open if you didn't press the right buttons under the hooded portion above the paper. (other companies also had this feature) It also had a lock on the front to lock the drawer & a lock to prevent the employees from removing the written records. It also had an internal lock that made the machine inoperable if it ran out of paper. I think this was very ingenious.
The following is only a small portion of the register that you may find. Read the first page as to how the numbering system worked.