Alonzo Johnson invented two calculating devices which functioned using a carry mechanism. The carry mechanism of the device is implemented by means of a smaller arm, which advances one digit, indicating hundreds, when the total on the inner disc exceeds 99. At each level of invention, Alonzo improved the machine’s functionality, making it a better version of the previous one. Besides the calculating machines, Alonzo also invented nut lock, spindle fastener, the machine for slitting lock nuts, car brakes, card cutter, sash fastener, and gumming device.

Who was Alonzo Johnson?

Alonzo Johnson, a machinist from Springfield, Massachusetts, is a holder of two U.S. patents for calculating devices: patent 73732 from 28 January 1868 and patent 85229 from 22 December 1868. The first patent was granted to Alonzo Johnson and James A. Loomis, who was also a machinist from Springfield. The patent models of both devices are still preserved in the National Museum of American History, Washington, D.C.

Quick Facts

Full Name
Alonzo Johnson
Children
Melissa H, Charles B, Laura Lovisa
Nationality
American
Place of Birth
Bangor, Maine
Fields of Expertise
  • Mechanical Engineering
  • Calculating Machine
Contributions
He invented two calculating machines, a nut lock, a spindle fastener, a machine for slitting lock nuts, car brakes, a card cutter, a sash fastener, gumming device

Early life

Alonzo Johnson was born on 12 February 1828, in Bangor, Maine. He was the son of Lovisa (Underwood) Johnson (26 October 1805-20 April 1835) and Dolliver Johnson (1800-1884). Dolliver Johnson from Bradford, Vermont, was a railroad engineer, then a superintendent of locomotive power on the Fitchburg Railroad, and finally associated with the Illinois Central at Duluth, Wisconsin. Beyond these details, much of Alonzo’s early family life remains a mystery.

Career

Machinist

Alonzo Johnson obviously was an imaginative man and an excellent machinist. He had two patents for calculating machines, which he invented and kept improving their functionalities. Also, he is the holder of 8 more patents for: nut lock (pat. US188055); spindle fastener (US203160); machine for slitting lock nuts (US231492); car brakes (US235152 and US247830); card cutter (US241372); sash fastener (US256144); gumming device (US397798).

What Did Alonzo Johnson Invent?

The first calculating machine of Alonzo Johnson

The first calculating device, patented by Johnson and Loomis, is used to add numbers up to 99. It was manufactured by James Loomis and Henry Conkey, another machinist from Springfield. It was a brass and steel device with overall measurements: of 4.3 cm x 18 cm x 18 cm.

Alonzo Johnson
The first calculating machine of Alonzo Johnson (© National Museum of American History, Washington, D.C.)

The device is painted black on the reverse side and has a green paper label glued with directions for use. It also has support attached to the back so it can sit at an angle.

The adder consists of two concentric brass discs, one rotating inside the other. The rim of the outer disc has numbers from 0 to 99 engraved around its edge. The inner disc has 100 small holes marked evenly around its edge, which are also numbered 0 to 99—two steel arms pivot at the center of the inner disc. The longer arm has a pin on the underside that fits into the holes and a small knob on the upper side so it can be rotated. A protruding pin set at 0 in the outer circle stops the motion of this arm.

The device has a carry mechanism. When the total on the inner disc exceeds 99, the smaller arm advances one digit, indicating hundreds. Hundreds cannot be entered directly. Sums of up to 9999 can be indicated.

The second calculating device

The second calculating device of Alonzo Johnson is an improved version of the first. It was a brass, wood, and steel device with overall measurements: 16.5 cm x 18.5 cm x 18.5 cm, used to add numbers up to 99.

This adder of Johnson also has as its base two concentric brass discs, one rotating inside the other. Again, the rim of the outer disc has the numbers 0 to 99 engraved around its edge. The inner disc has 100 small holes (also numbered 0 to 99) marked around its edge—two steel arms pivot at the center of the disc. The more extended arm has a pin on the underside that fits into the holes and a small knob on the upper side so it can be rotated. A protruding pin set at 0 in the outer circle stops the motion of the arm.

Alonzo Johnson
The second calculating machine of Alonzo Johnson (© National Museum of American History, Washington, D.C.)

The carry mechanism of the device is implemented by means of a smaller arm, which advances one digit, indicating hundreds, when the total on the inner disc exceeds 99. The number of hundreds entered appears in a window in a small disc on top of three relatively small gears concentric to the large discs. Hundreds cannot be entered directly. The adder has a handle that projects from the center of the back.

Alonzo Johnson: Marriage, Children, Tragedy, and Personal Life

Net Worth

There is no record of Alonzo’s net worth.

Marriage

Alonzo Johnson married Sarah E. Sinclair on 27 October 1850.

Children

Alonzo Johnson and his wife Sarah had three children: Melissa H. (b. 16 June 1854), Charles B. (b. 16 March 1857 – died 1919), and Laura Lovisa (b. 7 November 1858).

Tragedy

Alonzo Johnson died in 1905 in Springfield, Mass., and was buried in the local Oak Grove Cemetery.

Alonzo Johnson: Awards and Achievements

Patent for Calculating Machines

As a fervent machinist, Alonzo Johnson invented two calculating devices and got patented by Johnson and Loomis. He went on to earn more patents for nut lock (pat. US188055), spindle fastener (US203160), machine for slitting lock nuts (US231492), car brakes (US235152 and US247830), card cutter (US241372), sash fastener (US256144), and gumming device (US397798).

Alonzo Johnson: Complete Biography, History, and Inventions FAQs (Frequently Asked Questions) 

Who was Alonzo Johnson?

Alonzo Johnson, a machinist from Springfield, Mass., is a holder of two U.S. patents for calculating devices: patent 73732 from 28 January 1868 and patent 85229 from 22 December 1868.

What is Alonzo Johnson Known for?

Alonzo Johnson invented two calculating devices which functioned using a carry mechanism. The carry mechanism of the device is implemented by means of a smaller arm, which advances one digit, indicating hundreds, when the total on the inner disc exceeds 99. The number of hundreds entered appears in a window in a small disc on top of three relatively small gears concentric to the large discs. Hundreds cannot be entered directly. The adder has a handle that projects from the center of the back.

At each level of invention, Alonzo improved the machine’s functionality, making it a better version of the previous one. Besides the calculating machines, Alonzo also invented nut lock, spindle fastener, the machine for slitting lock nuts, car brakes, card cutter, sash fastener, and gumming device.

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