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
What Katy Did as Dorry, Bryn McAuley as Joanna, and Dean Stockwell as "Tramp". A 1972 UK movie adaptation, "Katy", starred Clare Walker, and the 1962 eight-part TV series made in the UK, also called "Katy", featured rising star Susan Hampshire in the title role. In 2015, author Jacqueline Wilson wrote her novel "Katy", which is a modern retelling of "What Katy Did". The August 2016 edition of Storytime featured a new illustrated adaptation with illustrations by Italian artist Marco Guadalupi. "What Katy Did" was followed by four sequels: "What Katy Did at School" in which Katy and Clover attend the fictional Hillsover