THE increase of the towns of Manhattan, as, for the sake of convenience, we shall term New York and her adjuncts, in all that contributes to the importance of a great commercial mart, renders them one of the most remarkable places of the present age. Within the distinct recollections of living men, they have grown from a city of the fifth or sixth class to be near the head of all the purely trading places of the known world. That there are sufficient causes for this unparalleled prosperity, will appear in the analysis of the natural advantages of the port, in its position, security, accessories, and scale.