I got a Burroughs adding machine for Christmas. Mine is serial number 3-347317 which means it was probably made between May 1916 and Feburary 1917. Per the video Classiest adding machine ever (1922) this is the "machine that built capitalism". Burroughs had an entire line of "figuring", "bookkeeping" and "adding" machines.
This adding machine still works which is very cool.