Barometers Realm

The eye-catching case of this mid-20th century Japan Regal Twist Barometer is made of a zinc alloy, likely Zamak, commonly used for die casting. This alloy resembles silver or chrome after galvanization. The case is adorned with an elegant ornament in the form of karakusa, a curling vine motif.

A metal bezel with a convex glass insert protects the exposed metal dial. The dial features two barometric scales with an unusual measurement range: one in millibars from 920 to 1090, and the other in London inches of mercury from 27" to 32", divided into 1/20th increments. The weather indication text is presented in English using a sans-serif font.

A distinctive feature of this barometer is its pointer hand, made of thin steel and painted red. The trend indicator needle is made of brass. The internal mechanism has a generally standard design, characterized by the presence of a small aneroid capsule, made of copper or its alloy, a flat bending spring, and a lever system.

Ota Instrument Manufacturing Co., Ltd. is a Japanese company founded in 1919 (the eighth year of the Taisho era). At the time of its founding, the company specialized in the production of glass thermometers, but over time, its activities expanded significantly. From the late Taisho era to World War II, influenced by the Great Kanto Earthquake and military requests, the company began manufacturing equipment for meteorological observations on land, at sea, and in the upper layers of the atmosphere.