On 1 January 1901, following a series of referendums, the six Australian colonies including Queensland federated to form Australia as a nation. Certain powers previously exercised by the Queensland Government were ceded to the federal government under the Constitution of Australia. At this time Queensland had a population of half a million people. In the same year, the Chillagoe smelters commenced operations. Brisbane was proclaimed a city in 1902. In 1905, women voted in state elections for the first time. In 1908, Witches Falls, now part of Tamborine National Park on Tamborine Mountain is declared the first national park in Queensland. The University of Queensland was established in 1909. The 1912 Brisbane General Strike lasted for five weeks.