In the previous year (1501) Tristan d'Acunha had been sighted by a Portuguese navigator of the same name, and on Ascension Day, Juan de Nova discovered the rocky islet of Ascension, and in the year following, St. Helena. Thomas Aubert visited Canada in 1508, and in 1512 Ponce de Leon, a Spanish navigator, coasted the peninsula of Florida. Balbao from the heights of Panama first saw the open expanse of the Pacific in 1513. An expedition was immediately fitted out to explore the newly-found ocean, and in 1516 Diaz de Solis traced the coasts of Brazil south, passed the bay of Rio Janeiro, and discovered the estuary of the La Plata. In the North Atlantic Bermudez made known the group called after him, the Bermudas. In September, 1519, Magellan sailed from San Lucar in command of a fleet of discovery, fitted out by Charles V. of Spain. Steering south past the La Plata, Magellan passed into the Pacific through the strait which still bears his name. Naming the adjoining land Tierra del Fuego, this intrepid navigator crossed the " Ocean° Pacifico " to the Philippines, where he was murdered. One of his vessels, however, held on its way, and ultimately reached Spain—this vessel, the "Vittoria," being thus the first to circumnavigate the globe.
The North American coast, from Florida to Newfound land, was becoming gradually better known, and in 1534 Canada was explored by Cortier, and taken possession of by France. The attempts made to discover a North-east Passage round Norway and Northern Asia, or a North west Passage through the North American Archipelago from the Atlantic to the Pacific, will be more particularly noticed in the historical notes on the Arctic Ocean ; suffice it to remark here that in 1576 Martin Frobisher discovered the strait leading into Hudson Bay, and eleven years later John Davis sailed through Davis' Straits. Hudson Bay itself was explored by the English navigator Hudson, who perished there in 1610. Three years before, John Smith had sailed up Chesapeake Bay, and the Straits of Le Haire and Staten Island was discovered by Le Maim and Schouten, who then doubled the southern extremity of South America, naming it Cape Horn, in honour of Hoorn, the native town of Schou ten. Along the American and African shores of the Atlantic, discovery was soon followed by settlement, and thus the French occupied Canada and Louisiana—the intervening territory being settled by the English and the Dutch, with the excep tion of Florida, held by the Spaniards, who also conquered Mexico and the Western States of South America. Brazil was retained by the Portuguese, who also possessed them selves of the greater part of the western shores of Africa, and founded settlements at Senegambia, Guinea, and Angola. In
1652 the Dutch founded the Cape Colony ; and the establish ment of the Hudson Bay Company in 1670 led to more minute exploration of the northern coasts of North America. In fact, by the year 1700 the coasts of the Atlantic were pretty accurately known, and much frequented. Since then the exploration of the other great oceans has been accomplished in such a manner, that the configuration, not only of the great continental land masses, but also of the smaller islands, and even reefs, banks, and shoals, has been accurately mapped out for the guidance of navigators.
What may be called the scientific exploration of the bed of the Atlantic dates from the year 1849, when the American Senate passed an Act authorising the employment of three vessels to assist Lieut. Maury in his researches. The officers of the United States Coast Survey devoted special attention to the "Gulf Stream." In 1871 the U.S.S. Mercury ran a line of soundings between Barbadoes and Sierra Leone. From 1868 to 1870, two of H.M.S., the Lightning and the Porcupine—explored the basin of the Atlantic from the Fame Islands to the Straits of Gibraltar. The celebrated Challenger expedition, specially equipped for the scientific exploration of the deep sea, left England in December 1872, and proceeded south to Lisbon, Gibraltar, Madeira, and the Canaries, whence it crossed the Atlantic to the West Indies. Thence it went north to Halifax and Newfoundland, and returned to Ber muda. Then it crossed the Atlantic, by the Azores, to Cape Verd Islands, and recrossed it again to Bahia, whence it pro ceeded, by Tristan d'Acunha, to Cape Town, arriving there at the close of 1873. The vessel then skirted the Indian and Antarctic Oceans, and explored the Pacific more fully, arriving at Valparaiso in 1875. Sailing thence through Magellan's Straits, and touching at the Falkland Islands, the expedition returned to England on the 24th of May, 1876.
From 1874 to 1876, other vessels were employed in exploring the basin of the Atlantic—such as the German frigate Gazelle, H.M.S. Valorous, the Norwegian vessel Voringen, and the U.S.S. Gettysburg. The data thus sup plied have enabled us to map out with considerable accuracy the conformation of the bed of the ocean, and more especially that of the Atlantic. The main results of the more recent investigations are embodied in the little chart which forms the frontispiece of this work, and which the student would do well to examine very carefully.