Johann von Lamont

Johann von Lamont
Johann Lamont, lithograph by Rudolf Hoffmann, 1856.
Born	13 December 1805 Corriemulzie
Died	6 August 1879 (aged 73) Munich, Germany
Nationality	Scottish
Known for	magnetism of the Earth
Scientific career
Fields	astronomy physics
Doctoral students	Philipp Carl

Johann von Lamont FRSE, also referred to as Johann Lamont (13 December 1805 – 6 August 1879), was a Scottish-German astronomer and physicist.

Born John Lamont on 13 December 1805, at Corriemulzie near Inverey in Aberdeenshire, Scotland. The son of Robert Lamont (forester to James Duff) and Elizabeth Ewan, his education began at the local school in Inverey, near Braemar. In 1817 his father died and John was sent to be educated at St James' monastery (Scots Benedictine College) at Ratisbon, Germany. He began to work in astronomy and joined the Bogenhausen Observatory, became its director in 1835, took his doctorate of philosophy in 1830 and became professor of astronomy in 1852 at Munich University. At the observatory he undertook the task of creating a star catalog that had about 35,000 entries.

In 1845 he was elected an Honorary Fellow of the Royal Society of Edinburgh.

His most important work was on the magnetism of the Earth. He performed magnetic surveys in Bavaria and northern Germany, France, Spain, and Denmark. He discovered a magnetic decennial period (ten-year cycle) and the electric current in the Earth closing the electric "circuit" creating the magnetic field in 1850. This roughly matched the eleven-year sunspot cycle discovered by Heinrich Schwabe.

He calculated the orbits of the moons of Uranus and Saturn, obtaining the first value for Uranus' mass. By chance he observed Neptune in 1845 and twice in 1846, but did not recognize the object as being a new planet.