History of Computers and Computing, Calculating tools, Gadgets, Jabez Burns

Jabez Burns in 1870
Key Points:
  • Jabez Burns invented an addometer, a machine for adding numbers that actually never went into production, but the original model resides in the Smithsonian.
  • Jabez Burns owned other patents for coffee equipment, a water-closet, and a windows-shade fixture.
  • Jabez Burns created Jabez Burns & Sons to manufacture an improved coffee roaster that he invented.

Jabez Burns’ Addometer

On August 24, 1858, Jabez Burns (1826-1888), an inventor from New York (see biography of Jabez Burns), took out the US patent №21,243 for a machine for adding numbers. The device obviously never went into production, and only the patent model survived to the present time (property of Smithsonian National Museum).

The device is a small 4/5 positional addometer (adder) (4 digits in input, and 5 digits in output mechanism), made by wood, tin, brass, and paper; measurements: 16 cm x 38.7 cm x 12.2 cm.


It is a simple lever-set adding machine with wooden sides and metal covers for the back and the lower front (see the lower photo). The four large toothed wheels (visible on the front side), are used for setting numbers, with five registering wheels in front and below these. Between each of the large wheels there is an inscribed strip of metal, with the digits from 0 to 9 indicated along the edges of these strips. Each of the four right registering wheels, divided into ten parts, is attached to a spur wheel with ten teeth that meshes with a large toothed wheel.

Placing a finger in one of the teeth of a large wheel and rotating it forward advances the registering wheel proportionally. The number entered is visible in a row of windows at the front of the model. The four registering wheels to the left have on their left side a ring of ten equidistant pins that are used in carrying.

The patent model of Burns

Other Inventions of Jabez Burns

Besides the adding machine, Jabez Burns was an inventor of other devices, but they were complimentary to an industry where he had much working experience–coffee. In 1864, he founded a trademark company called Jabez Burns & Sons in order to manufacture a coffee roaster model that he himself had invented. He held patents for other types of coffee equipment, as well as for a windows shades fixture and a water-closets.

His rise to inventor was an interesting one. His career began as a cart man in the 1850’s, then a peddler and a bookkeeper, before he finally broke into being an inventor and company owner. His company was actually bought out in 1964 by a larger one, which still recognizes his brand to this day.


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