The ample accessions to geography, by the discovery of many islands within the tropic in the Pacific Ocean, in the course of this voyage, which was carried on with singular perseverance between three and four years, have been already stated to the reader. But the general search now made throughout the whole southern hemisphere, as being the principal object in view, hath been reserved for this separate article. Here, indeed, we are not to take notice of lands that have been discovered, but of seas sailed through, where lands had been supposed to exist. In tracing the route of the Resolution and Adventure throughout the South Atlantic, the South Indian, and the South Pacific Oceans that environ the globe, and combining it with the route of the Endeavour, we receive what may be called ocular demonstration, that Captain Cook, in his persevering researches, sailed over many an extensive continent, which, though supposed to have been seen by former navigators, at the approach of his ships, sunk into the bosom of the ocean, and, “_like the baseless fabric of a vision, left not a wreck behind._”[26] It has been urged, that the existence of a southern continent is necessary to preserve an _equilibrium_ between the two hemispheres. But however plausible this theory may seem at first sight, experience has abundantly detected its fallacy. In consequence of Captain Cook’s voyage, now under consideration, we have a thorough knowledge of the state of the southern hemisphere, and can pronounce with certainty, that the _equilibrium_ of the globe is effectually preserved, though the proportion of sea actually sailed through, leaves no sufficient space for the corresponding mass of land, which, on speculative arguments, had been maintained to be necessary.[36] If former navigators have added more land to the known globe than Captain Cook, to him, at least, was reserved the honour of being foremost in disclosing to us the extent of sea that covers its surface. His own summary view of the transactions of this voyage, will be a proper conclusion to these remarks: “I had now made the circuit of the Southern Ocean in a high latitude, and traversed it in such a manner as to leave not the least room for there being a continent, unless near the pole, and out of the reach of navigation. By twice visiting the Tropical Sea, I had not only settled the situation of some old discoveries, but made there many new ones, and left, I conceive, very little to be done, even in that part. Thus I flatter myself, that the intention of the voyage has, in every respect, been fully answered; the southern hemisphere sufficiently explored; and a final end put to the searching after a southern continent, which has, at times, engrossed the attention of some of the Maritime Powers for near two centuries past, and been a favourite theory amongst the geographers of all ages.”[37]