Mujin Light (Tanaka Hisashige’s System) 無尽灯

In the Edo period, most lamps used rapeseed oil, which is more viscous than kerosene and thus is absorbed by the wick more slowly. The result was that the lamp produced a dimmer light. Near the end of the Edo period, several types of mujin or everlasting lamps were developed to provide brighter and more stable lighting. The example shown here is the best known type, employing what is known as Tanaka Hisashige’s system. It applies the principle of the air gun, in which compressed air produced by an air pump is used to shoot projectiles. In this application, compressed air makes it possible to supply lamp oil to the wick steadily and smoothly. These lamps generated light about ten times brighter than a small candle and could burn all night long with no need to replenish the oil. Tanaka Hisashige (1799-1881) was from Kurume in Kyushu. Fascinated by mechanical contrivances at a time when machines and the techniques for building them were rare novelties, he invented a host of mechanized products, from mechanical dolls to perpetual clocks, that earned him the nickname “Giemon the mechanical whiz.” He later opened a shop and factory on the Ginza that became the starting point of today’s Toshiba.