Macaroni box model Comptometer, ID no. MA.311192. This model was the prototype for the Comptometer, the first commercially successful adding machine with a mechanism driven by pushing the keys. Comptometers were used primarily in businesses and government offices. Dorr E. Felt made the model from a wooden box that had been used to ship macaroni. © Smithsonian Institution; photo 89-13536 by Rick Vargas