Computer Timeline

In the middle 1860s the young Swedish engineer Carl Helge Julius Palmcrantz (1842-1880), who just finished his studies at the Teknologiska Institutet (Technological Institute of Stockholm) and returned unemployed (there was a recession with a large shortage of work in Sweden) to his parental home in Jämtland, was trying to..Read More

On 25 September 1866, Samuel J. Kelso of Detroit, Michigan, obtained a patent (US patent №58347, assigned to himself and James Edgar, of New York) for a ciphering machine. The calculating machine of Kelso was a simple adding device, quite similar to one of the machines of the French inventor..Read More

On 18th December 1866, John H. Chidester of Cleveland, Ohio, patented a simple adding device (see US Letters Patent No. 60475) that was quite similar to the earlier machines of his compatriots Jabez Burns and John Ballou. The Computing Machine of Chidester (see the nearby patent drawing) obviously never went..Read More

On 18 February 1867, François Marie Auguste Barre, a Parisian merchant, got a 15-year patent for Machine à compter (calculating machine, see the French patent N° 75026). In the same year, the device was presented during the Exposition Universelle (International Exposition, the second world’s fair was held in Paris, from..Read More

On 13 August 1867, Amos Mendenhall, a merchant and amateur mechanic from Cerro Gordo, Randolph County, Indiana, patented an improved calculating machine (US patent Nr. 67786). The patent model of the device (up to 1880, the US Patent Office required inventors to submit a model with their patent application) is..Read More