Leiden University at the university. The learning and reputation of Jacobus Gronovius, Herman Boerhaave, Tiberius Hemsterhuis and David Ruhnken, among others, enabled Leiden to maintain its reputation for excellence down to the end of the 18th century. At the end of the nineteenth century, Leiden University again became one of Europe's leading universities. At the world’s first university low-temperature laboratory, professor Heike Kamerlingh Onnes achieved temperatures of only one degree above absolute zero of −273 degrees Celsius. In 1908 he was also the first to succeed in liquifying helium and can be credited with the discovery of the superconductivity in metals. The
Kamerlingh Onnes (crater) northeast. Kamerlingh Onnes (crater) Kamerlingh Onnes is a lunar impact crater on the far side of the Moon. It lies less than a crater diameter to the north-northwest of the crater Kolhörster. North of Kamerlingh Onnes lies Shternberg and to the northwest is Weyl. This is a worn and eroded crater formation that is slightly elongated along the east–west direction, giving it a somewhat oval shape. A number of small craters lie along the rim, particularly along the northern side. The interior floor is marked only by a few small craterlets, and some ray material from the crater Ohm to