Introduction of the Comptometer by Felt & Tarrant Co
Introduction of Comptometer by Felt & Tarrant Co of Chicago
"Dorr E. Felt began working on what would become the Comptometer in 1885, making the first working version in metal in 1886 (the 1885 model was made mostly of wood and spare parts), and began low volume production by hand in 1887. Felt went into partnership with Robert Tarrant to produce and refine the Comptometer over many years. Although rather common due to their relatively high production, the Comptometer is an historically significant machine, being the first successful multiple order key driven calculator. Felt's new carrying mechanism was complex, but it met the high speed requirement of a key driven calculator. The 8 column Comptometer could add faster than an accountant's brain, which was its key to success."
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