Other Nations took their part in these explorations, and the honour of finding a New World did not rest with our ancestors. But in more recent days the Lion’s share of research has undoubtedly fallen to the British; and the coast-lines of the world have been surveyed and mapped out chiefly by ships of the British Royal Navy. Up to the beginning of the Nineteenth Century, all vessels, small or large, moved by means of the wind or by oars. Then began a change of immense importance, due to the use of steam for carrying ships across the sea, not only with but in the teeth of the wind. This method took hold and prevailed, though at first very slowly. Even in the present day hosts of merchant-ships still travel by means of sails only, making systematic use of the Trades and other steadfast winds. When time is not a prime consideration, sailing is of course far cheaper than steaming. On the other hand, the carrying power of a steamer is about three times that of a sailing-vessel of the same size, since it can generally perform three journeys in the same time that a sailing-vessel can manage one. All over the world, in every sea, are thousands upon thousands of ships of every kind and description, night and day speeding onward, each to its destined port. Lines of Passenger-ships regularly plough the main, starting on fixed days, and seldom failing to arrive on fixed days. Merchant ships innumerable follow certain routes, going from country to country over the Ocean, carrying the world’s produce. Mighty Navies of war-vessels, huge in bulk and terrible in possibilities, rest like sleeping leviathans upon the bosom of the deep, or steam from point to point with resistless energy. All this denotes a wonderful change since the days, when a few roughly-made boats used to creep round the coasts of a few inhabited countries. Wide though the ocean be, with thousands of miles of water unbroken save by occasional islands, the number of ships now always at sea is so great, that the perils of collisions are much increased. But this, of course, is chiefly in the more frequented routes, not in Ocean’s lonelier wastes. Definite rules are laid down for the avoidance of collisions. When two vessels meet, each must steer “to the right.” All ships have to carry, after dark, two powerful lights: a green one on the starboard or right side; a red one on the port or left side; and in the case of steamers, a white light also must be seen upon the mast. The gradual development of ships, in the course of centuries, from rude skin-covered coracles to top-heavy mediæval vessels; from them to the stately Wooden Walls of Old England,--and, lastly, to the massive Ironclads of the Empire; is full of interest. By far the more rapid part of this development was witnessed in the years of the Nineteenth Century. Perhaps a slight comparison between past and present sizes of ships may be worth giving. To begin with Passenger Vessels.