Dieppe maps
From Wikipedia, the free encyclopedia
The Dieppe maps are a set of maps produced in Dieppe, France in the 16th century, thought to provide clues towards Portuguese exploration of Australia two hundred years before Captain Cook and earlier than the first confirmed sighting of Australia by Jansz in 1606. The maps show part of what might be Queensland, and name the land mass "Java a Grande".
The first historian to put these maps forward as evidence of Portuguese discoveries was George Collingridge, who published The Discovery of Australia in 1895, claiming (unpopularly) that Australia was discovered by other nations than the British long before Cook's 1770 voyage.
Kenneth Gordon McIntyre, in his book The Secret Discovery of Australia: Portuguese Ventures 200 Years Before Captain Cook (1977), describes in detail the method by which he believes the Dieppe maps were produced from sailors' charts of the Australian coast. He believes that despite the secretive nature of the Portuguese naval administration, information was leaked to the mapmaking school at Dieppe, who incorporated this information in their maps between 1536 and 1550. Discrepancies in the resulting maps have been attributed to the difficulties of navigating without a reliable method of determining Longitude, and the techniques used to convert maps to different projections.
