Kunitomo Ikkansai
Encyclopedia
was a Japanese gun manufacturer of the early 19th century, who, after having spent several months in Edo
where he could get accustomed with Dutch wares, built Japan's first reflective telescope in 1831. It was of the Gregorian
type.
Kunitomo's telescope had a magnification
of 60, and allowed him to make very detailed studies of sun spot
s and lunar topography. Four of his telescopes remain to this day.
Kunimoto also developed manufacturing methods for guns, and also created an air gun
based on rangaku
knowledge acquired from the Dutch
in Dejima
.
Edo
, also romanized as Yedo or Yeddo, is the former name of the Japanese capital Tokyo, and was the seat of power for the Tokugawa shogunate which ruled Japan from 1603 to 1868...
where he could get accustomed with Dutch wares, built Japan's first reflective telescope in 1831. It was of the Gregorian
Gregorian telescope
The Gregorian telescope is a type of reflecting telescope designed by Scottish mathematician and astronomer James Gregory in the 17th century, and first built in 1673 by Robert Hooke...
type.
Kunitomo's telescope had a magnification
Magnification
Magnification is the process of enlarging something only in appearance, not in physical size. This enlargement is quantified by a calculated number also called "magnification"...
of 60, and allowed him to make very detailed studies of sun spot
Sun SPOT
Sun SPOT is a wireless sensor network mote developed by Sun Microsystems. The device is built upon the IEEE 802.15.4 standard...
s and lunar topography. Four of his telescopes remain to this day.
Kunimoto also developed manufacturing methods for guns, and also created an air gun
Air gun
An air gun is a rifle , pistol , or shotgun that fires projectiles by means of compressed air or other gas, in contrast to a firearm, which burns a propellant. Most air guns use metallic projectiles as ammunition. Air guns that only use plastic projectiles are classified as airsoft...
based on rangaku
Rangaku
Rangaku is a body of knowledge developed by Japan through its contacts with the Dutch enclave of Dejima, which allowed Japan to keep abreast of Western technology and medicine in the period when the country was closed to foreigners, 1641–1853, because of the Tokugawa shogunate’s policy of national...
knowledge acquired from the Dutch
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
in Dejima
Dejima
was a small fan-shaped artificial island built in the bay of Nagasaki in 1634. This island, which was formed by digging a canal through a small peninsula, remained as the single place of direct trade and exchange between Japan and the outside world during the Edo period. Dejima was built to...
.
Other uses of the name
- 6100 Kunitomoikkansai6100 Kunitomoikkansai6100 Kunitomoikkansai is a main-belt asteroid discovered on November 9, 1991 by A. Sugie at the Dynic Astronomical Observatory.- External links :*...
, a main belt asteroid discovered in 1991, is named after Kunitomo Ikkansai.