As late as 1861 an exploring ship was visited by natives of Western Australia, riding simple rough logs. To smooth and sharpen the log’s end and then to hollow it out has been thought to be the first step taken by primitive man in his progress toward a boat; but I think the dugout probably came later, or at any rate no earlier, than the folding of bark into a trough and tying up the ends, as some savages are still content to do. In North America, where materials were favorable, this germ developed into the very highest type of canoe—the Algonkin birch-bark. It may have been an attempt to imitate the bark canoe in a more durable form which led to the laborious hollowing of dugouts; but here again, in regions where suitable trees grew, the art developed so highly as to produce the great sea-boats of the Papuans and our Northwest Coast Indians, carved from a single log, yet able to carry sixty or more persons and their luggage. Such boats as these, when provided with sails, are practically “ships,” and satisfy every need of their owners. Another root of naval architecture lies in the raft, which long ago reached a high degree of usefulness in the sea-going balsa of western South America. It is probable that the South Sea catamaran is a clever outgrowth of experience with a raft. In Polynesia it took the form of two great canoes, exactly equal, fastened close together and covered by a single central deck; and such are the seaworthiness and speed of these double boats, that the Polynesians voyage hundreds of miles in them. Similar in purpose—namely, to insure stability—are the various outriggers that at once characterize and distinguish among themselves the native craft of the South Seas. This device consists of a beam of the lightest obtainable wood, usually about half as long as the canoe, which rests upon the water parallel to and a few feet away from the side of the boat, and is connected with its gunwale by elastic rods or planks. Sometimes these are covered, or partly covered, by a light platform, and there are many variations in form; but the idea in all cases is to keep the boat from overturning. In many parts of the world logs could be obtained large enough only for a narrow bottom or hollowed keel, and the remainder of the boat was built up of planks and pieces ingeniously pegged and knit together with treenails, ratan, and cords made of vegetable fibers that tightened when wet. The Madras surf-boats are a familiar example in civilized waters of boats made in this way which have great elasticity, and out of them have developed, without much change, the swift proas of the Malays, and the junks of China, Korea, and Japan. One device for stitching these boats firmly together was the leaving of ridges on the inner side of the planks or pieces, through holes in which they could be tied to each other and to the inner framework without making a hole reaching the outside. This system seems to have been earlier than the use of treenails.