Lightning Adding Machine

Here's an odd item I ran across years ago in a second-hand shop. The Lightning Adding Machine.

The metal mechanism sits in a stand made of bakelite. You can turn the metal dials with a stylus, and when a dial goes past 9, the next dial increments by 1. Numbers show in little windows above the dials.

An included instruction sheet shows how you can use this device to add, subtract, multiply, or divide. "As simple as dialing a phone... and instant in response!" You could order another Lightning Adding Machine for only $12.95 postpaid, from the Lightning Adding Machine Co., 543 S. Spring St., Los Angeles 13, Calif.

Just from the look of things, I'd guess that this little mechanical adding machine dates from the 1940s.