The calculator, the quick ally of millions of people. Accountants, merchants, students … its uses are endless. We have to remember that the current model had several developments. One of them is the first mechanical calculator, essentially the same as what is currently in use. It was called a comptometer and was patented by its inventor on a day like today, October 11, 1887.
His name was Dorr Felt. It was proposed to improve the existing calculators. Like Thomas Hill and Blaise Pascal, his model set precedents. During the harvest festival (USA) of 1884 he started his first prototype of a comptometer.
Ingenuity and skill
To build it, he used a box of macaroni for the outer armor. He added meat skewers, staples, and rubber bands (which doubled as feathers). So he strengthened the internal mechanism. This first prototype was called the Box of macaroni.
Soon after, Robert Tarrant, the owner of a workshop in Chicago, became interested in the proposal. He gave Felt a wage of $ 6 a week. He would then add up to $ 5,000 to build his first practical machine, which was completed in the fall of 1886.
8 machines had been built by September 1887. Felt founded in January 1889 Felt & Tarrant Manufacturing Company, a major company in the calculator industry until the mid-1970s.
The system that will stay here
It was the first calculator that worked just by pressing keys. You no longer had to turn the wheels like before. The new process offered sufficient speed, reliability and economy.
Each key adds or subtracts its value from the accumulator as soon as it is pressed. An experienced operator can enter all digits of a number at the same time with as many fingers as necessary. This is why it is sometimes faster to use than electronic calculators. The comptometer was used in special applications until the 1990s. With the exception of museum pieces, all have been replaced by electronic calculators and computers.
It was manufactured non-stop from 1887 to the mid-1970s and was constantly improved. A number of electromechanical models were added in the 1930s. It was the first mechanical pocket calculator to have a fully electronic motor in 1961. It was the ANITA Mark VII model that was launched by Sumlock comptometer.
It was mostly an adder, but it could do subtraction, multiplication, and division. His keyboard consisted of eight or more columns, each with nine keys. Special comptometers with different sets of keys have been made for a variety of special purposes. The calculation of currency, time and imperial weight also changes. The name Comptometer has been used as a generic name for this type of calculating machine.
A lot of water has flowed under the bridge since the first mechanical keystroke calculator. Computers seem to have made every remnant of the past obsolete. But the time in which this machine saved mankind in working hours during its existence remains incalculable.