Eise Eisinga
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Eise Jeltes Eisinga (Dronrijp, 21 February 1744 - Franeker, 27 August 1828) was a Dutch amateur astronomer who built an orrery in his house in Franeker, Netherlands. The orrery still exists and is the oldest in the world.
[edit] Introduction
Eisinga was the son of a wool comber. Although he was moderately gifted, he wasn’t allowed to go to school. When he was only 17 he published a book regarding the principles of astronomy. Eisinga became a wool comber in Franeker, Netherlands, and educated himself in mathematics and astronomy through self-education and at the Franeker Academy. At the age of 24 he married Pietje Jacobs (? – 24th July 1788) and they had three children, one girl and two boys.
- Trijntje (April 1773 – 26 April 1773)
- Jelte (29 May 1774 – 31 March 1809)
- Jacobus (17 March 1784 – 24 March 1858)
Due to a political crisis in 1787, he had to leave Friesland and went to Germany. Later he moved to Visvliet where he worked as a wool comber. He was banned from Friesland for five years and therefore stayed in Visvliet. Meanwhile his wife died, and on 27 May 1792 he married Trijntje Eelkes Sikkema (21 February 1764) in Visvliet. They had one son and two daughters.
- Eelke (14 October 1793 – 28 May 1795)
- Hittje (16 February 1796 – 8 May 1843)
- Minke (4 June 1798 – 17 July 1870)
In 1795 he returned to Franeker. Eisinga became a professor at the Franeker Academy, until in 1811 Napoleon ordered it to be closed. Eisinga died on 27 August 1828, at the age 84.
[edit] Orrery
On 8 May 1774 a conjunction of the moon and the planets Mercury, Venus, Mars, Jupiter would appear, Reverend Eelco Alta, from Bozum, Netherlands, published a book in which he predicted that the planets and the moon would collide, with the result that the earth would be pushed out of its orbit and burned by the sun. Due to this prediction there was a lot of panic in Friesland. To prove that there was no reason for panic, Eisinga decided to build an orrery in his living room. He expected to finish it within six months and eventually finished it in 1781, 7 years after he started. During the same year Uranus was discovered, but for this planet there was no room on the ceiling of his livingroom, where there orrery was located.
On 30 June 1818 King Willem I and Prince Frederik visited the orrery. King Willem I bought the orrery for the Dutch state. In 1859 the orrery was donated by the Dutch state to the city of Franeker. In Eisinga's the working of the orrery was described.
