When did Matthew flinders prove tasmaina is an island?

Matthew Flinders proved that Tasmania is an island during his exploration in 1798-1800. His circumnavigation of Tasmania, which he completed in 1798, provided clear evidence that it was separated from the Australian mainland by the Bass Strait. This finding was significant in mapping and understanding Australia's geography. Flinders published his results in his 1814 work, "A Voyage to Terra Australis."