The first place among the rivers of the globe is due to the Amazon, if not for the length of its course, yet for the volume of its waters. It traverses the equatorial regions of South America, chiefly in a direction from west to east, and has its embouchure nearly under the equator. Its mouth was discovered in the year 1500 by Pinzon, one of the captains who sailed with Columbus on his first voyage; and thirty nine years afterward, the stream was traced downward from Peru by Francisco Orellana, whose name was given to the river by his countrymen, to preserve the memory of his bold enterprise. But the Spaniard’s report of having met with armed women on its banks, deprived him of the honor, for it originated the common title of the river of the Amazon. Its principal affluents rival the largest rivers of the Eastern continent, as appears from the following statement of their supposed lengths-- Miles. Ucayali 1350 Yutai 750 Jaura 750 Madeira 1800 Topayos 1000 Xingu 1080 Napo 800 Rio Negro 1400 The width of the Amazon averages from one to two miles in the upper parts of its course, but toward its termination its opposite banks are seen with difficulty, and it widens to between twenty and thirty miles, which is about its breadth upon joining the Atlantic. For two thousand miles in a direct line from the ocean, the river is navigable by vessels of any burden; for, at the confluence of the Tunguragua and Ucayali, where the Amazon--properly so called--commences, no bottom was found in March, 1836, with a line of 35 fathoms, or 210 feet. The tide rushes up its channel with immense violence at the period of the full moon, in two, three and sometimes four successive waves, each presenting a perpendicular front of from ten to fifteen feet. When the tide ebbs in the rainy season, the liberated waters of the river rush out of their channel with tremendous force, and create a current in the ocean, which is perceptible five hundred miles from its mouth. It is difficult to sound the river, owing to the rapidity of its current, which runs commonly at the rate of from three to four miles an hour--a momentum not arising from the inclination of its bed, the fall of which is very gradual, but from the immense quantity of water which descends in it. The climate of its basin is, perhaps, the most humid to which any country is subject. The quantity of rain which annually descends upon this region, has not been ascertained with precision; but taking that at the town of Maranhão as a sample, which is not less than two hundred inches, the amount of rain poured upon the district of the Amazon every year must be prodigious. The heat also is excessive through the whole