Editing Royal Observatory, Greenwich (section)

== Magnetic observations ==
[[File:"The Magnetic Pavilion" - Royal Observatory Greenwich ca 1900 (7890151714).jpg|thumb|The Magnetic Pavilion, 1900]]
The first magnetic observation was taken in 1680 by the first Astronomer Royal, John Flamsteed, using a magnetic needle from the Royal Society.<ref name="Malin-1996">{{Cite journal|title=1996QJRAS..37...65M Page 65|journal = Quarterly Journal of the Royal Astronomical Society|volume = 37|pages = 65|bibcode = 1996QJRAS..37...65M|last1 = Malin|first1 = S. R. C.|year = 1996}}</ref> The second and third Astronomers Royal, [[Edmond Halley]] and then James Bradley, also took some magnetic measurements during their tenure.<ref name="Malin-1996" />

In the 19th century George Airy established the Magnetical and Meteorological Department.<ref name="Malin-1996" />

The first Magnetic House was built next to the observatory but by 1900 a second, about 300–400 metres from the main observatory, was built to reduce magnetic interference.<ref name="HMSO-1921">{{Cite book|url=https://books.google.com/books?id=adA0AQAAMAAJ&q=magnetic+pavilion+built+greenwich&pg=RA2-PR2|title=Observations Made at the Royal Observatory, Greenwich in the Year ... in Astronomy, Magnetism and Meteorology|date=1921|publisher=H.M. Stationery Office|language=en}}</ref> Both houses were made of non-magnetic materials.<ref name="HMSO-1921" /> The older building was called the Magnet House, but iron added to buildings in the 1890s at the observatory was throwing off measurements, so the instruments were moved to the Magnetic Pavilion.<ref name="HMSO-1921" /> A new Magnetograph House was also completed by 1914.<ref name="HMSO-1921" />

One of the special events that occurred in the study of magnetism was when [[François Arago]] and [[Alexander von Humboldt]] took magnetic observations at Greenwich in 1822.<ref name="1986JBAA...97...26H Page 26">{{Cite journal|title=1986JBAA...97...26H Page 26|journal = Journal of the British Astronomical Association|volume = 97|pages = 26|bibcode = 1986JBAA...97...26H|last1 = Howard-Duff|first1 = I.|year = 1986}}</ref> In 1825 Arago won the [[Copley Medal|Copley Gold Medal]] for this research<ref name="1986JBAA...97...26H Page 26"/> (see also [[Arago's rotations]]).