The 20th century is a time of ubiquity and decline of mechanical calculating machines. In the first half of the century thousands of companies, primarily in Germany and USA, manufactured millions of mechanical calculators, cash registers, accounting machines, etc. In the second half however, especially after 1960s, when the first electronic calculators were launched (see the Pocketronic of Kilby), the mechanical calculators started their unavoidable journey to the museum collections.
|Alexander Rechnitzer (1900)||Hopkins (1902)|
|Ryoichi Yazu (1902)||Dalton (1902)|
|Wales (1903)||Mathias Bäuerle (1903)|
|Emory Ensign (1904)||Gauss (1905)|
|Victor (1918)||Curta (1948)|