Willem Henri Julius

from Wikipedia, the free encyclopedia
Willem Henri Julius

Willem Henri Julius (born August 4, 1860 in Zutphen , † April 15, 1925 in Utrecht ) was a Dutch physicist.

Life

Willem Henri was born as the son of the later director of the higher middle school Willem Julius (born October 26, 1834 in Utrecht; † November 19, 1907 there) and his wife Maria Margaretha Dumont, who married on August 18, 1859 in Utrecht (born March 23, 1835 in Utrecht; † May 4, 1917 in Baarn). He had attended the high school in Gouda himself and on September 27, 1879 began studying natural sciences at the University of Utrecht . In 1882 he became an assistant at the Utrecht Institute of Physics with Christophorus Henricus Didericus Buys Ballot and in 1888 with his uncle Victor August Julius (born May 11, 1851 in Utrecht; † May 1, 1902 ibid). In addition, he worked from 1887 to 1890 as a physics and chemistry teacher at the bourgeois evening school in Utrecht and received his doctorate under Buys Ballot on February 10, 1988 with the thesis Het warmtespectrum en de trillingsperioden derolekulen van eenige gassen (German: The heat spectrum and the oscillation periods of the molecules of some gases ) to a doctorate in science.

In 1889 he drew attention to himself with the work The Light and Heat Radiation Burned Gases , which he had submitted to the Association for the Promotion of Industry in Berlin and which was awarded a gold medal. Thereupon he got an appointment as associate professor of physics at the University of Amsterdam on October 29, 1890 , which office he took on February 2, 1891 with the inaugural speech De methoden van onderzoek in de natuurkunde (German: The methods of investigations in physics ) started. On August 6, 1896, Julius was appointed full professor of experimental physics, metrology and physical geography at the University of Utrecht, as well as director of the physical institute in Utrecht, which he did on October 17 of the same year with the introductory speech Kritiek in de natuurkunde (German: Critique in Physics ) began.

His scientific work focused on spectrophotometry and astronomical heliophysics. He completed expeditions to Sumatra in 1901, to Burgos in 1905 and to Maastricht in 1912 to investigate the solar eclipse. In 1907 he also worked at the Mount Wilson Observatory in California. Julius also took part in the organizational tasks of the Utrecht University and was rector of the Alma Mater in the academy year 1907/08 . In 1897 he became a member of the Royal Dutch Academy of Sciences , in 1899 a member of the Hollandsche Maatschappij der Wetenschappen in Haarlem and in 1908 became a Knight of the Order of the Dutch Lion .

family

Julius married on December 23, 1890 in Utrecht Betsij Mathilde Frederique Einthoven (born March 21, 1867 in Samarang (Indonesia); † July 10, 1945 in Utrecht), the daughter of Jacob Einthoven (born February 26, 1825 in Groningen; † 17 September 1866 in Semarang (Indonesia) and his wife Louise Marie Mathilde Caroline de Vogel (born July 14, 1833 in Semarang (Indonesia), † May 4, 1923 in Utrecht). The marriage has a son and two daughters. From the children we know:

  • Willem Otto Julius (born April 7, 1898 in Utrecht, † July 4, 1973 in Purley (England)) married. with Emilie Gvendolyn Woolrich Perry (1905–2001)
  • Marie Wilhelmina Elisabeth Julius (* October 8, 1894 in Amsterdam, † August 21, 1977 in Hilversum)
  • Louise Maria Julius (born December 8, 1891 in Amsterdam, † August 24, 1982 in Laren)

Works (selection)

  • The warm spectrum en de trilling periods of the molecules from a few streets. Utrecht 1888 ( online )
  • The light and heat radiation of burned gases. Berlin 1890
  • De methods van onderzoek in de natuurkunde. Amsterdam 1891
  • Bolometric onderzoek van absorptiespectra. Amsterdam 1892
  • Trilvrije opstelling van meetinstrumenten. 1895
  • Criticism in de natuurkunde. Utrecht 1896
  • Preliminary report of the Dutch expedition to Karang Sago (Sumatra) for the observation of the total solar eclipse of May 1901. Amsterdam 1902
  • Les Théories solaires et la Dispersion anomale. Paris 1904
  • Polarimetric study of the corona; Heat radiation from the sun during the eclipse. Amsterdam 1905
  • Energievervoer in de electronenwereld. Utrecht 1908
  • Le déplacement de raies de dispersion dans les specters d'absorption. Paris 1917
  • Leerboek of the zonnephysica. Groningen 1928 (2nd edition)

literature

  • HAM Snelders: Julius, Willem Henri (1860-1925). In: Biographical Woordenboek van Nederland. (BWN) The Hague, 1985, Vol. 2, ( Online )
  • AA Nijland: WH Julius †. In: Nieuwe Rotterdamsche Courant. of April 16, 1925, p. 2, (accessed July 8, 2016, online )
  • Klaus Hentschel: Julius and the anomalous dispersion: facets of the history of a failed research program. April 1991 ( online )

Web links

  • Julius in the Catalogus Professorum Academiae Rheno-Traiectinae
  • Julius in the professorial catalog of the University of Amsterdam
  • Julius entry at the Royal Dutch Academy of Sciences
  • Julius at the digital library of Dutch literature