Terra Australis Incognita
Terra Australis Incognita (Latin: 'the Unknown Southern Land'), a.k.a. Terra Australis Nondum Cognita ("the Southern Land Not Yet Known") or Terra Australis Recenter Inventa Sed Nondum Plene Cognita ("The Southern Land, recently discovered but not yet fully known"). was a hypothetical continent first posited in antiquity.
Notions of a yet-to-be-discovered continent derived from the concept that the hemisphere needed a land mass to balance Europe, Asia and North America.
Notions of Terra Australis date back to Roman times and beyond. They were commonplace in medieval geography, thanks to Ptolemy's maps, which showed Africa extending towards the South Pole), with the Indian Ocean landlocked.
During medieval times, the concept gained popularity across Europe, though whether the continent was habitable remained controversial.
During the Age of Discovery, European mariners proved Africa was surrounded by sea, and their discoveries reduced the area where the continent might be located.
Discoveries and unconfirmed sightings were often considered parts of the hypothetical continent.
The first depictions of Terra Australis on globes came in the 16th century.
Based on Magellan's passage into the Pacific, they showed an immense region stretching south from Tierra del Fuego towards the South Pole, newly discovered but not surveyed.
After that, cartographic depictions of the southern continent varied wildly but shrank as voyages across previously uncharted waters eliminated potential locations.
By the eighteenth century, it was clear that New Holland (Australia) was separate from the imagined continent, with New Zealand (first seen by Abel Tasman in 1642) possibly representing the continent's west coast.
Alexander Dalrymple's Historical Collection of the Several Voyages and Discoveries in the South Pacific Ocean (1770–1771). suggested a continent inhabited by more than fifty million people, stretching across 100 degrees of longitude, more extensive "than the whole civilized part of Asia, from Turkey to the eastern extremity of China".
Dalrymple's suggestion aroused the British government's interest, and they used James Cook's Endeavour (voyage 1768-71) to investigate the matter after its official purpose (observing the transit of Venus) was complete.
Although some critics, including Dalrymple, disagreed, Cook's voyage effectively sounded the death knell for Terra Australis Incognita.
Investigating the waters southeast of Tahiti drew a blank. Circumnavigating New Zealand proved the islands did not connect to anything more significant.
The criticism prompted Cook's second voyage (1772-75), which explored the waters beyond 40 degrees south latitude and investigated sightings in warmer waters during the southern winter.
Cook's circumnavigation at a very high southern latitude, even crossing the Antarctic Circle, demonstrated that any southern continent must lie well within the cold polar region.
Until Cook's voyages finally put paid to the notion, the imagined and unexplored southern continent was a frequent setting for fantastic fiction and imaginary journeys.
