It is not only the best harbor on our coast, but that in easiest communication with other parts of the country. To the other portions of the coast it is as nearly central as it could be without losing fatally in other respects. Delaware and Chesapeake Bays afford fine roadsteads; but the low sand barrens and wet alluvial flats which form their shores compelled Philadelphia and Baltimore to retire their population such a distance up the chief communicating rivers as to deprive them of many important advantages proper to a seaport. Under the influence of free ideas may be expected a wonderful development of the advantages of Chesapeake Bay. Good husbandry and unshackled enterprise throughout Maryland and Virginia will astonish Baltimore by an increase of her population and commerce beyond the brightest speculative dreams. The full resources of Delaware Bay are far from being developed. Yet Philadelphia and Baltimore are forever precluded from competing with New York, both by their greater distance from open water and the comparative inferiority of the interior tracts with which they have ready communication. Below Chesapeake Bay the coast system of great river-estuaries gives way to the Sea-Island system, in which the main-land is flanked by a series of bars or sandbanks, separated from it by tortuous and difficult lagoons. The rivers which empty into this network of channels are comparatively difficult of entrance, and but imperfectly navigable. The isolation of the Sea Islands is enough to make them still more inconvenient situations than any on the main-land for the foundation of a metropolis. Before we have gone far down this system, we have passed the centre where, on mathematical principles, a metropolis should stand. Considered with regard to the tributary interior, New York occupies a position no less central than with respect to the coast. It is impossible to study a map of our country without momently increasing surprise at the multiplicity of natural avenues which converge in New York from the richest producing districts of the world. The entire result of the country's labor seems to seek New York by inevitable channels. Products run down to the managing, disbursing, and balancing hand of New York as naturally as the thoughts of a man run down to the hand which must embody them. From the north it takes tribute through the Hudson River. This magnificent water-course, permitting the ascent of the largest ships for a hundred miles, and of river-craft for fifty miles farther, has upon its eastern side a country averaging about thirty miles in width to the Taconic range, consisting chiefly of the richest grazing, grain, and orchard land in the Atlantic States. Above the Highlands, the west side of the river becomes a fertile, though narrower and more broken agricultural tract; and at the head of navigation, the Hudson opens into another valley of exhaustless fertility,--that of the Mohawk,--coming eastward from the centre of the State.