The first and most obvious light in which the sea presents itself from the political and social point of view is that of a great highway; or better, perhaps, of a wide common, over which men may pass in all directions, but on which some well-worn paths show that controlling reasons have led them to choose certain lines of travel rather than others. These lines of travel are called trade routes; and the reasons which have determined them are to be sought in the history of the world.

Notwithstanding all the familiar and unfamiliar dangers of the sea, both travel and traffic by water have always been easier and cheaper than by land. The commercial greatness of Holland was due not only to her shipping at sea, but also to the numerous tranquil water-ways which gave such cheap and easy access to her own interior and to that of Germany. This advantage of carriage by water over that by land was yet more marked in a period when roads were few and very bad, wars frequent and society unsettled, as was the case two hundred years ago. Sea traffic then went in peril of robbers, but was nevertheless safer and quicker than that by land. A Dutch writer of that time, estimating the chances of his country in a war with England, notices among other things that the water-ways of England failed to penetrate the country sufficiently; therefore, the roads being bad, goods from one part Of the kingdom to the other must go by sea, and be exposed to capture by the way. As regards purely internal trade, this danger has generally disappeared at the present day. In most civilized countries, now, the destruction or disappearance of the coasting trade would only be an inconvenience, although water transit is still the cheaper. Nevertheless, as late as the wars of the French Republic and the First Empire, those who are familiar with the history of the period, and the light naval literature that has grown up around it, know how constant is the mention of convoys stealing from point to point along the French coast, although the sea swarmed with English cruisers and there were good inland roads.

Under modern conditions, however, home trade is but a part of the business of a country bordering on the sea. Foreign necessaries or luxuries must be brought to its ports, either in its own or in foreign ships, which will return, bearing in exchange the products of the country, whether they be the fruits of the earth or the works of men's hands and it is the wish of every nation that this shipping business should be done by its own vessels. The ships that thus sail to and fro must have secure ports to which to return, and must, as far as possible, be followed by the protection of their country throughout the voyage.

This protection in time of war must be extended by armed shipping. The necessity of a navy, in the restricted sense of the word, springs, therefore, from the existence of a peaceful shipping, and disappears with it, except in the case of a nation which has aggressive tendencies, and keeps up a navy merely as a branch of the military establishment. As the United States has at present no aggressive purposes, and as its merchant service has disappeared, the dwindling of the armed fleet and general lack of interest in it are strictly logical consequences. When for any reason sea trade is again found to pay, a large enough shipping interest will reappear to compel the revival of the war fleet. It is possible that when a canal route through the Central- American Isthmus is seen to be a near certainty, the aggressive impulse may he strong enough to lead to the same result. This is doubtful, however, because a peaceful, gain-loving nation is not far-sighted, and far-sightedness is needed for adequate military preparation, especially in these days.

As a nation, with its unarmed and armed shipping, launches forth from its own shores, the need is soon felt of points upon which the ships can rely for peaceful trading, for refuge and supplies. In the present day friendly, though foreign, ports are to be found all over the world and their shelter is enough while peace prevails. It was not always so, nor does peace always endure, though the United States have been favored by so long a continuance of it. In earlier times the merchant seaman, seeking for trade in new and unexplored regions, made his gains at risk of life and liberty from suspicious or hostile nations, and was under great delays in collecting a full and profitable freight. He therefore intuitively sought at the far end of his trade route one or more stations, to be given to him by force or favor, where he could fix himself or his agents in reasonable security, where his ships could lie in safety, and where the merchantable products of the land could be continually collecting, awaiting the arrival of the home fleet, which should carry them to the mother-country. As there was immense gain, as well as much risk, in these early voyages, such establishments naturally multiplied and grew until they became colonies whose ultimate development and success depended upon the genius and policy of the nation from which they sprang, and form a very great part of the history, and particularly of the sea history, of the world. All colonies had not the simple and natural birth and growth above described. Many were more formal, and purely political, in their conception and founding, the act of the rulers of the people rather than of private individuals but the trading-station with its after expansion, the work simply of the adventurer seeking gain, was in its reasons and essence the same as the elaborately organized and chartered colony. In both cases the mother-country had won a foothold in a foreign land, seeking a new outlet for what it had to sell, a new sphere for its shipping, more employment for its people, more comfort and wealth for itself.