|Manufactured by||Omoto Iron Works (Now, TIGER CALCULATING MACHINE Co., Ltd.)|
|Owner||The National Museum of Nature and Science, Tokyo|
|Location of historical materials||The National Museum of Nature and Science, Tokyo
7-20 Ueno Park, Taito-ku, Tokyo 110-8718 Japan
|Visitor information||Open to the public|
|Contact||The National Museum of Nature and Science, Tokyo Tel.+81-3-5777-8600
In 1923, Omoto Torajiro began selling a mechanical desktop calculator called the "Tora Brand Calculator" named form his first name. This calculator was an improved version of the Brunsviga mechanical desktop calculator for which Omoto had obtained a patent. The mechanical calculator was first commercialized in the 19th century by a Frenchman, Charles Thomas, and later was mass-produced by firms like the Brunsviga Company of Germany. At the beginning of the 1900s, it appears that about 50 of these machines were imported to Japan. Tora Brand was not first maker of it in Japan. However Tora's Calculator would not sell because Japanese people didn't trust in Japanese manufactures in those days. Later, Torajiro changed Japanese name "Tora" to the foreign-sounding "Tiger", and became so common that "Tiger" became synonymous with the mechanical calculator. Tiger Calculator No.59 had the mark of Tiger Brand was an early machine made by this shop. Around the middle of the 1950s, the price was ¥35,000, and it drove out foreign products for reasons of both price and performance. The cumulative number of machines sold reached a little less than 500,000 units. It was widely used until the latter half of the 1950s, and was sold until the spread of electronic calculators at the end of the 1960s. Although it was said to be for desktop use, it weighed as much as 6 kilograms.