The American river-steamboat--the palatial American _steamboat_, as distinguished from the dingy, clumsy English _steamer_--is another of the means by which Art has supplemented New York's gifts of Nature. This magnificent triumph of sculpturesque beauty, wedded to the highest grade of mechanical skill, must be from two hundred and fifty to four hundred feet long,--must accommodate from five hundred to two thousand passengers,--must run its mile in three minutes,--must be as _rococo_ in its upholsterings as a bedchamber of Versailles,--must gratify every sense, consult every taste, and meet every convenience. Such a boat as this runs daily to every principal city on the Sound or the Hudson, to Albany, to Boston, to Philadelphia. A more venturous class of coasting steamers in peaceful times are constantly leaving for Baltimore, Wilmington, Charleston, Savannah, Key West, Mobile, New Orleans, and Galveston. The immense commerce of the Erie Canal, with all its sources and tributaries, is practically transacted by New York City. Nearly everything intended for export, plus New York's purchases for her own consumption, is forwarded from the Erie Canal terminus in a series of _tows_, each of these being a rope-bound fleet, averaging perhaps fifty canal-boats and barges, propelled by a powerful steamer intercalated near the centre. The traveller new to Hudson River scenery will be startled, any summer day on which he may choose to take a steamboat trip to Albany, by the apparition, at distances varying from one to three miles all the way, of floating islands, settled by a large commercial population, who like their dinner off the top of a hogshead, and follow the laundry business to such an extent that they quite effloresce with wet shirts, and are seen through a lattice of clothes-lines. Let him know that these floating islands are but little drops of vital blood from the great heart of the West, coming down the nation's main artery to nurse some small tissue of the metropolis; that these are "Hudson River tows"; and that, novel as that phenomenon may appear to him, every other fresh traveller has been equally startled by it since March, and will be startled by it till December. Another ministry to New York is performed by the _night-tows_, consisting of a few cattle, produce, and passenger barges attached to a steamer, made up semi-weekly or tri-weekly at every town of any importance on the Hudson and the Sound. We will not include the large fleet of Sound and River sloops, brigs, and schooners in the list of New York's artificial advantages. Turning to New York's land communication with the interior, we find the following railroads radiating from the metropolitan centre.