The New Student's Reference Work/Amazon

Am′azon, a river of South America, flowing easterly from the Andes to the Atlantic, where it empties below the equator.  It is the largest river on the globe, but not the longest.  Its length is estimated at from 3,000 to 4,000 miles; its width, at its mouth, is 60 miles; it is four miles wide 1,000 miles from the sea; and more than a mile wide 2,000 miles from the sea.  Its depth for 750 miles is nowhere less than 175 feet.  Over 350 branches and lesser tributaries form its main trunk, and the whole system drains an area of 2,500,000 square miles, or more than a third part of South America.  While large vessels can sail from the sea over the main river and its branches, the volume of water is perceptible in the ocean 200 miles from the coast, and the influence of the tides is felt 400 miles from its mouth.  The forests are very extensive, being so twisted and matted and interlaced with trees, vines and shrubs, as to present an almost impassable barrier.  This “sea of verdure,” a traveler says, “extends in an unbroken, evergreen circle of 1,100 miles in diameter.”  The mouth of the Amazon was discovered by Pinzon in 1500.  It was not ascended until forty years later.  It is navigable for over 2,000 miles, and with its branches it affords 16,000 miles of navigable waters.