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 rack behind."[29] 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.[30] [Footnote 29: A very long note in the original is occupied by Mr Wales's reply to the observations of Monsieur le Monier, in the memoirs of the French Academy of Sciences for 1776, respecting what Captain Cook alleged in the account of his second voyage, of the non-existence of Cape Circumcision, said to have been discovered by Bouvet in 1738. As the subject, though exceedingly well treated by Mr Wales, is in itself of scarce any importance, and has long lost interest among scientific enquirers, who rest perfectly content with Captain Cook's examination, there appeared no inducement whatever to retain the note. The reader, it is confidently presumed, will be satisfied with what was said of it in the account of the former voyage.--E.] [Footnote 30: The judgment of the ingenious author of _Recherches sur Américains_, on this question, seems to be very deserving of a place here: "Qu'on calcule, comme on voudra, on sera toujours contraint d'avouer, qu'il y a une plus grande portion de continent située dans la latitude septentrionale, que dans la latitude australe.