Johannes Diderik van der Waals higher temperatures. Nitrogen, oxygen, hydrogen, and helium subsequently succumbed to liquefaction. Heike Kamerlingh Onnes was significantly influenced by the pioneer work of van der Waals. In 1908, Onnes became the first to make liquid helium; this led directly to his 1911 discovery of superconductivity. Van der Waals started his career as a school teacher. He became the first physics professor of the University of Amsterdam when in 1877 the old Athenaeum was upgraded to Municipal University. Van der Waals won the 1910 Nobel Prize in physics for his work on the equation of state for gases and liquids. Johannes Diderik
Johannes Bosscha Kamerlingh Onnes was his assistant from 1878 to 1882, after which Kamerlingh Onnes became professor at Leiden University. In 1885 Boscha needed to resign as director because of poor health. His "Verspreide Geschriften" (Diverse Writings) were published in three volumes (Leyden, 1902). In 1855 he married Paulina Emilia Kerkhoven in the town of Voorst. They had four daughters and two sons. The Bosscha Observatory on Java has been named after his son Karel Albert Rudolf Bosscha (1865–1928), who contributed much to the technical development of Indonesia. Johannes Bosscha Johannes Bosscha Jr. (18 November 1831 – 15 April 1911) was a