Star Globe, Celestial Navigation, Japanese

Star globes function by giving approximate elevations and azimuths of navigational stars for a hemisphere in a specific year. They provide a navigator who is operating in an unfamiliar region a quick reference for preparing a sextant "shot." Star globes began appearing for maritime use in the late nineteenth century and were used as late as 1980. Their primary application was in long nautical voyages. This Japanese example was acquired by the Army Air Forces as part of their technical collection. While aeronautical use of star globes is largely unknown, the acquisition of this globe in an aeronautical context suggests it may have been employed by the Japanese long-range aircraft program that took the form of the Tachikawa Ki-77 aircraft intended to operate a non-stop shuttle service between Tokyo and Berlin, either by flying north of the Soviet Union or across the Indian Ocean and Iran to occupied German territory. One attempt at the latter route resulted in the loss of the aircraft, but another survived the war.