C. H. D. Buys Ballot

Buys Ballot studied at Utrecht University. Otto Johannes Adriaan de Haart, Eiso Henricus Groenman and Dirk Adriaan Kerkhoff are recorded as having studied under C. Buys Ballot. The recorded working language is Dutch. Employment is recorded with Utrecht University and Royal Netherlands Meteorological Institute. Positions recorded include rector of Utrecht University. Distinctions recorded are Knight Grand Officer of the Order of Franz Josef I, Knight of the Order of the Netherlands Lion and 2nd Class Order of the Crown.

• Name — C. H. D. Buys Ballot • Birth Name — Christophorus Henricus Diedericus Buys Ballot • Born — 10 October 1817 • Birthplace — Kloetinge, Netherlands • Died — 3 February 1890 • Place of death — Utrecht, Netherlands • Fields — chemistry meteorology • Education — Utrecht University • Doctoral Students — Willem Henri Julius • Known for — Buys-Ballot's law

• Illustration — Ballot in 1857 Ballot was born on 10 October 1817, in Kloetinge, to a Dutch Reformed minister. He attended the Gymnasium at Zaltbommel and the University of Utrecht. After receiving his doctorate in 1844, he became lecturer in mineralogy and geology at Utrecht; he added theoretical chemistry in 1846. In 1847, he was appointed professor of mathematics and from 1867 until his retirement he was professor of physics. He died in Utrecht, on 3 February 1890, aged 72. In 1970, the lunar crater Buys-Ballot, on the far side of the Moon, was named in his honour.

Buys Ballot tested the Doppler effect for sound waves in 1845 by using a group of musicians playing a calibrated note on a train in the Utrecht-Amsterdam line. • Illustration — Wall art in Utrecht depicting a study of the Doppler effect Buys Ballot is best known for his accomplishments in the field of meteorology, specifically the explanation of the direction of air flow in large weather systems. Furthermore, he founded the Royal Dutch Meteorological Institute in 1854 and he remained its chief director until his death. He was one of the first to see the need for international cooperation, and in 1873 he organized and became the first chairman of the International Meteorological Organization, a precursor of the World Meteorological Organization (WMO). Buys Ballot's law states that if a person in the Northern Hemisphere stands with his back to the wind, the atmospheric pressure is low to the left, high to the right. His main research effort in meteorology went into examining long-time series for regularities; he was more concerned with establishing the regularities than in explaining them. He made no contributions to the theory of meteorology, despite his training in physics. Buys Ballot devised a tabular method for investigating periodicity in time series. In 1847, he used the table now named after him to determine the period of the sun's rotation from daily observations of temperature in the Netherlands from 1729 to 1846. Buys Ballot became member of the Royal Netherlands Academy of Arts and Sciences in 1855 and an honorary member of the Finnish Society of Sciences and Letters in 1887. Among his students was the prominent Dutch astronomer Jacobus Kapteyn.