SYDNEY, AUSTRALIA—According to a BBC News report, indigenous Australians made traditional tools from flint cobbles carried to Australia as ballast on British ships in the eighteenth and nineteenth centuries. The flint tools were among 100 to 200 culturally significant items that were found among tens of thousands of pieces of stone during construction work in what is now suburban Sydney. “This site doesn’t just contain the flint material, it contains a variety of other artifacts that show Aboriginal people working there,” said archaeologist Tim Owen of GML Heritage. Owen traced the flint to the Thames River, where convict ships were loaded with ballast for the journey to Australia. Chemical analysis revealed the samples Owen collected in London were identical to the worked flint uncovered in Sydney. For more on flint in the archaeological record, go to “Evolve and Catch Fire.”