Learned geographers have gone back to very remote times, even to the Middle Ages, and, by the aid of old maps, have set up ingenious theories showing that the Australian continent was then known to explorers. Some evidence has been adduced of a French voyage in which the continent was discovered in the youth of the sixteenth century, and, of course, it has been asserted that the Chinese were acquainted with the land long before Europeans ventured to go so far afloat.