Mathematical Treasure: Model Cash Register Designed by the Ritty Brothers

Peggy A. Kidwell (National Museum of American History, Smithsonian Institution)

Prototype or Replica of Ritty Model 1 Cash Register, circa 1904

Ritty Model #1 Cash Register, made by 1904, Smithsonian Institution negative number 73-3169.

In the second half of the 19th century, merchants increasingly hired strangers to work in their stores. To tally purchases and track money passing through their businesses, they turned to cash registers. This is the prototype for a cash register designed by the brothers James and John Ritty of Dayton, Ohio. Their machine had a large, clock-like face and a row of keys for entering amounts from 5 cents to 95 cents (by fives) and from $1 to $9. A mechanism inside the machine recorded total sales. Patents taken out by the Rittys became the basis of the firm of National Cash Register, which went on to sell much more elaborate cash registers worldwide. This model was exhibited by NCR in 1904 as an example of the beginning of their business.

For a more complete discussion of this and other cash registers in the collections of the Smithsonian’s National Museum of American History, see

Index of Mathematical Treasures

Index of Mathematical Objects