It was in 1880 that the lessons of towing experiments with models began to be adopted in practice. As a result the forms of steamers have been greatly improved. Originally their lines were taken from those of sailing vessels but, as dimensions grew bolder and speeds were increased, it became clear that steamers demanded wholly different lines of their own. These lines, fortunately, may be plainly disclosed in experiments with a model, because a steamer usually runs on an even keel, in which position a model is easily driven through a tank. A sailing vessel, on the contrary, is nearly always heeled over by the wind so that it seldom runs on an even keel; tank experiments, therefore, avail but little for the improvement of its lines. Even were the model inclined at various angles in one test after another, sails must be omitted, with their influence on steering, their lifting and burying effects, often extreme. [Illustration: 1. Starboard Side. 2. Horizontal Sections. 3. Vertical Sections. 4. Central Longitudinal Section. 5. Part of the Gunwhale inside, with its Skirting in Front and in Section. 6. _Section through AB._ 7. Bird’s Eye View. THE VIKING SHIP.] A Viking Ship a Thousand Years Old. A thousand years ago the Vikings of Norway roved the seas in boats of a form which is admired to-day. To those hardy adventurers swiftness and seaworthiness meant nothing less than life and victory, their eyes perforce were keen to note what craft sped fastest through the water, what new curves kept waves from coming aboard. Perchance as they refined upon keel and rib they took golden hints from the shapes of gulls and fish. To be sure, long before science was dreamt of, they had to work by rule-of-thumb, but the thumb was joined to brains that did honor to human nature. On page 56 is illustrated the Viking Ship unearthed early in 1880 at Godstad, near Sandefjord in Norway, in a mound where, according to tradition, a king and his treasure had been buried. It is the most complete and the best preserved vessel of ancient date in existence. It is fully described and pictured in “The Viking Ship,” by Mr. N. Nicolaysen, a work published in 1882 by Mr. Albert Cammermeyer, Christiania. Mr. Nicolaysen regards the vessel as having been built about A. D. 900, for use in war by the great chieftain whose tomb it became. The ship was 65 feet, 10 inches long, on the keel; with an extreme length over all of 78 feet, 1 inch; amidships it was 16 feet, 9 inches; its depth amidships from the top of the bulwarks to the keel was 3 feet, 11-1/4 inches. The material throughout was pine. The helm, a plank shaped like a broad oar, was fastened to the side of the vessel. In accordance with the number of its oars and shields this ship must have had a crew of sixty-four, besides these came the steersman, the chieftain and probably a few more of his companions, making a total, in all likelihood, of seventy to be carried by her. Says Mr. Nicolaysen: