This year is the 175th anniversary of European settlement in South Australia. The University of Adelaide presented a series of public lectures collectively called Turning Points in South Australian History. Bill Gammage gave the first and showed by an accretion of primary sources that, prior to white settlement in 1836, Aborigines kept a tidy landscape thanks to the controlled use of fire. First Adelaidians exclaimed that the landscape was close to an English garden. Henry Reynolds gave the second lecture, and made much of the political and social timing of the settlement, after the abolition of slavery in London and just before the Treaty of Waitangi in New Zealand. The idea of terra nullius was in its preliminary colonial tatters.