View from the north.
Christophorus Henricus Diedericus Buys Ballot was the third professor (after Haring and Mulder) to be appointed at Utrecht University.
Buys Ballot was appointed lecturer in 1845, extraordinary (buitengewoon) professor in mathematics in 1848, full professor in mathematics in 1857 and physics in 1867. He retired in 1888.
Interested and knowledgeable in many fields, he found it hard to choose between the sciences and humanities. In the forties he developed a speculative theory explaining everything in chemistry and physics by a system of attracting matter and repelling ether particles. Dissuaded from publishing by Mulder, he was disappointed and "took up meteorology as a toy [speelpop]".
His most famous contribution to science is the explanation of the direction of air flow in large weather systems. It was observed that air flows around areas of high (or low) pressure; in the northern hemisphere, the flow is counter clockwise around lows and clockwise around highs. In the southern hemisphere the directions are reversed. Buys Ballot explained that, due to the rotation of the earth, air doesn't just flow from high to low pressure, but follows the pressure gradient lines, in the directions observed. The rotation introduces an apparent force (coriolis force) on the moving air particles causing them to veer (right in the northern hemisphere, left in the southern hemisphere), until the coriolis force balances the pressure force.
Buys Ballot is the founder and first director of the KNMI, Koninklijk Nederlands Meteorologisch Instituut (Royal Dutch Meteorological Institute), established by Royal Decree in 1854, januari 31. The Institute's first location was Sonnenborgh, a 16th century castle-like part of the walls around Utrecht, then used as an observatory. Buys Ballot paid for the necessary adaptations. KNMI was the first research institute funded by the Dutch government.
Buys Ballot saw the necessity of international cooperation. In 1873, he became the first chairman of the International Meteorological Committee, a precursor of the World Meteorological Organization (WMO).
bron: Kennis als Opdracht: De Universiteit Utrecht 1636-2001, Herve Jamin, 2001, Matrijs.