The prototype of Dorr Felt’s key-driven Comptometer did not begin in a polished office-machine case. Its mechanisms sit inside a scarred wooden box originally used to transport macaroni. The container holds levers and wheels for a five-column adding machine, turning pasta packaging into the chassis of an arithmetic device.

The keyboard is equally provisional. One partial column uses wooden skewers as keys; four are now missing. Number dials face the operator from the front, allowing the rough box to display the state of a calculation even while its controls still look like workshop stand-ins.

That contrast makes the prototype legible as an idea under construction. The box establishes boundaries and supports the mechanism. The skewers let fingers communicate with levers. The dials return the result. None of those jobs requires the finished product’s later visual authority.

The Smithsonian identifies this object as the prototype for the Comptometer, a key-driven adding machine. Before the office appliance acquired a manufactured case and complete keyboard, its central relationship was already present: press a key, move a mechanism, change a number. The pasta had left the box; calculation moved in.