Dick, who was quite rested again, did as I advised, and managed to get from one end of the vessel to the other, although it must be confessed that more water ran down his throat than he found pleasant.  I then showed him how he could tread water, by keeping his body perfectly upright with his arms folded; here was a still greater surprise to him, and he was thus able to keep his chin well out of the water, and sometimes, by striking hard, to raise his shoulders even above the surface.