Hordern House is an Australian bookseller, and "the Great South Land" naturally includes their home. However, it would be totally wrong to consider this an Australian catalogue. Its subject is a much wider land, even if most of it would in time prove to be illusory. The "antipodes" refers to land directly opposite on the globe to others, that is, reached by running a straight line from one point, through the center of the Earth, to another. In the days before the Age of Discovery, Europeans had some knowledge of much of the Northern Hemisphere (excluding North America), but almost none of its antipodes, the Southern Hemisphere. The result was much speculation, and some fundamental misunderstandings as to what was on the other side.
Some of these earlier books contained descriptions, even drawings, of the creatures that supposedly lived down there. What possessed people to believe such things lived in the Southern Hemisphere is hard to know. However, what was the most fundamental belief about the world to the south was that there existed a massive southern continent, extending from the South Pole almost to the edges of South America and Africa, and still farther north into the Pacific Ocean. The primary explanation for this belief was as explorations began into the Southern Hemisphere, it was realized that there was much less land there than in the Northern Hemisphere. This upset the firm belief in antipodal balance. Scholars concluded there must be a balancing continent in the unknown part of the Southern Hemisphere, its far south. This would be the dominant theory about the southern half of the globe all the way up until James Cook's second voyage, when he sailed deep into what was supposed to be part of the southern continent with still no land in sight.
This catalogue does not contain the voyages of Cook or those who put the southern continent to rest, or put the final touches on the outlines of Australia. Instead, it ranges from works of the ancient Greeks and Romans and their vision of the world, to the earliest eastern explorers - Marco Polo and John Mandeville, to the early Age of Discovery up to the early years of the 18th century, when the southern continent was still alive, and Australia, or New Holland, had been discovered, but was still an amorphous mass whose true nature was yet unknown. Here are a few of these works.
Item 3 is an early printing of Pomponius Mela's Cosmographia, sive De situ orbis, just the fourth printed edition of this ancient text, published in Venice in 1478. Pomponius Mela was an ancient Roman geographer, whose work was well over a millennium old by this time, but still, along with Ptolemy, the most up to date geography. Pomponius believed that the southern half of the globe was unreachable because of a belt of impenetrable heat that separated the two halves. Nonetheless, he still believed there must be a balancing, huge southern continent at the bottom (or top if you will) of the Earth. Priced at AU $36,000 (Australian dollars, or roughly $37,283 in American dollars).