I might enumerate among the causes of the lowering of the temperature at Cuba during the winter months, the great number of shoals with which the island is surrounded, and on which the heat is diminished several degrees of centesimal temperature. This diminished heat may be assigned to the molecules of water locally cooled, which go to the bottom; to the polar currents, which are borne toward the abyss of the tropical ocean, or to the mixture of the deep waters with those of the surface at the declivities of the banks. But the lowering of the temperature is partly compensated by the flood of hot water, the Gulf Stream, which runs along the north-west coast, and the swiftness of which is often diminished by the north and north-east winds. The chain of shoals which encircles the island and which appears on our maps like a penumbra, is fortunately broken on several points, and those interruptions afford free access to the shore. In the south-east part the proximity of the lofty primitive mountains renders the coast more precipitous. In that direction are situated the ports of Santiago de Cuba, Guantanamo, Baitiqueri and (in turning the Punta Maysi) Baracoa. The latter is the place most early peopled by Europeans. The entrance to the Old Channel, from Punta de Mulas, west-north-west of Baracoa, as far as the new settlement which has taken the name of Puerto de las Nuevitas del Principe, is alike free from shoals and breakers. Navigators find excellent anchorage a little to the east of Punta de Mulas, in the three rocks of Tanamo, Cabonico, and Nipe; and on the west of Punta de Mulas in the ports of Sama, Naranjo, del Padre and Nuevas Grandes. It is remarkable that near the latter port, almost in the same meridian where, on the southern side of the island, are situated the shoals of Buena Esperanza and of Las doce Leguas, stretching as far as the island of Pinos, we find the commencement of the uninterrupted series of the cayos of the Old Channel, extending to the length of ninety-four leagues, from Nuevitas to Punta Icacos. The Old Channel is narrowest opposite to Cayo Cruz and Cayo Romano; its breadth is scarcely more than five or six leagues. On this point, too, the Great Bank of Bahama takes its greatest development. The Cayos nearest the island of Cuba and those parts of the bank not covered with water (Long Island, Eleuthera) are, like Cuba, of a long and narrow shape. Were they only twenty or thirty feet higher, an island much larger than St. Domingo would appear at the surface of the ocean. The chain of breakers and cayos that bound the navigable part of the Old Channel towards the south leave between the channel and the coast of Cuba small basins without breakers, which communicate with several ports having good anchorage, such as Guanaja, Moron and Remedios.