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2010/1/342 Pocket slide rule with case, Sun, closed frame, glass / celluloid / bamboo / metal, made by the Hemmi Bamboo Slide Rule Manufacturing Co Ltd, Japan, 1917-1929. Click to enlarge.

Sun Hemmi pocket slide rule

Over the 19th and much of the 20th centuries the slide rule was the primary instrument for calculation used by many people engaged in the trades and in engineering. Although originally invented in the 17th century, and widely used for gauging (or estimating the quantities of certain products such as alcoholic spirits) it took until around 1850 for the slide rule to become generally popular with those for whom mathematics was a daily task. This was largely brought about through the increase in …


Object No.


Object Statement

Pocket slide rule with case, Sun, closed frame, glass / celluloid / bamboo / metal, made by the Hemmi Bamboo Slide Rule Manufacturing Co Ltd, Japan, 1917-1929

Physical Description

Slide rule, closed frame, single sided, double-sided slide, beige coloured celluloid laminate nailed to bamboo body. There is a transparent glass cursor in reverse "C" shaped metal frame, with a hairline printed on it in red. Tables of decimal inch equivalents, Weight of metals, Ultimate Strength of metals and timbers on reverse.

In very well used black card case with paper label on case, case is heavily repaired with sticky tape.

Scales: Mannheim
Stock, upper: A
Slide: B, C
Slide, reverse: S, L, T
Stock, lower: D
5inch ruler on upper bevelled edge,15cm ruler on lower squared edge


Manufacturer's mark and model number on cursor, embossed, on top ' SUN ', on bottom ' No. 58115 '. Patent numbers on slide rule stock, on bottom, printed in black ' Hemmi Sun Patent No. 22129. British Patent 107562, Brevette S.G.D.C. Made in Japan '. White paper label on reverse, handwritten in black pen ' Bromely 1980-99 '. Scratch on bottom ' W F C O X '.

Manufacturer's mark on card case, on left side, printed on paper label in red and black ' Sun / Hemmi's Bamboo Slide Rule / Tokyo, Japan / Established 1895 '. (partley illegibility)



Made by the Hemmi Bamboo Slide Rule Manufacturing Co Ltd, Japan, 1917-1929



Japan began to open up to the US [1] and Europe prior to and during the Meiji restoration of the late 19th century. [2] The new imperial administration sent out many diplomats and bureaucrats to investigate the technologies of the United States and Europe for application to the industrialisation of Japan. According to William Lise [3], an example of a Mannheim slide rule was brought back to Japan after Dr. Ritaro Hirota and Toragoro Kondo, who was the Head of the Construction Section of the Internal Affairs Ministry, visited Europe. This example appears to have been provided to the company Nakamura Surveying Instruments where Jiro Hemmi worked in dividing scales for use on surveying and other instruments. He began researching the manufacture of slide rules for Nakamura in 1895 and sometime between then and 1899, established his own company, Hemmi Jirou & Co., to manufacture them. [4]

He also began researching the use of materials indigenous to Asia for making slide rules settling on bamboo, and in 1912 Hemmi received a Japanese patent for a slide rule with a stock made from bamboo with scale faces of celluloid laminated to the bamboo stock. The patent was reinforced by a British patent of 1917 and an American patent in 1920. The type of bamboo [phyllostachys pubescens] comes from Japan's southernmost island Kyushu and has a large diameter making it more suitable for the flat body of the slide rule. It has a light yellow colour and is easy to mill into strips with the tongue and groove arrangement that allows the slider to slip smoothly in the channel provided by the stocks. [5]

In 1917, the company adopted the "Sun" trademark as a reflection of Japan's rising sun symbol which "was thought to bode well for the future of the firm's business" [6]. The Hemmi Co continued to improve their slide rules, developing in 1923 a new machine for dividing the scales. This brought greater accuracy to the mass production of their slide rules and they began exporting to the US [Post], Canada [Hughes-Owens] and Europe. They also developed new scales, patenting the Pythagorean scales (P and Q) for ?(a2 + b2) in 1925. In 1928 the company became Hemmi Seisakusho & Co and their rules are now marked "SUN Hemmi". By the mid-1930s the company was producing 40,000 slide rules per year. [7]

Sales to the US dropped off with WWII and slide rules were no longer marked "Made in Japan". After the war, the company was renamed Hemmi Keisanjaku [Hemmi Slide Rule Company] and between 1945 and 1951, their export slide rules were marked "Made in Occupied Japan". In the mid 1950s representatives from various companies selling Hemmi slide rules visited the Hemmi company in Japan to develop further export arrangements. These visitors included a Mr. A Richardson from E. Esdaile and Sons P/L of Sydney in 19565 and Mrs E.A. Esdaile in 1958. [8]

Jirou Hemmi died in 1953 having retired from the company in 1941. In the 1950's Hemmi Keisanjaku began manufacturing slide rules out of plastic. It is estimated that before the stopped producing in 1976 they manufactured 15 million slide rules. [9]

[1] With the arrival of Commodore Perry's ships in Japan, c 1853
[2] When imperial rule was restored in Japan after the defeat of the Tokugawa Shogunate, c.1867-1869
[3] William Lise, "History of Hemmi Slide Rule and Misc Japanese Slide Rule dates." [] and apparently drawn from a large general catalogue published by Hemmi Slide Rule in 1960.
[6] William Lise, op cit [3]
[7] Peter Hopp, Slide Rules, their History, Models and Makers, Mendham, New Jersey: Astragal Press, 1999.
[8] William Lise, op cit [3]


Credit Line

Donated through the Australian Government's Cultural Gifts Program in memory of Associate Professor Allan Bromley, 2010

Acquisition Date

19 January 2010

Cite this Object


Sun Hemmi pocket slide rule 2022, Museum of Applied Arts & Sciences, accessed 4 February 2023, <>


{{cite web |url= |title=Sun Hemmi pocket slide rule |author=Museum of Applied Arts & Sciences |access-date=4 February 2023 |publisher=Museum of Applied Arts & Sciences, Australia}}