The origin of navigation is unknown. It has baffled the research of antiquaries, for the simple reason that men sailed upon the sea before they committed the records of their history to paper, or that such records, if any existed, were swept away and lost in the periods of anarchy which succeeded. Imagination has suggested that the nautilus, or Portuguese man-of-war, raising its tiny sail and floating off before the breeze, first pointed out to man the use which might be made of the wind as a propelling force; that a split reed, following the current of some tranquil stream and transporting a beetle over its glassy surface, was the first canoe, while the beetle was the first sailor. Mythology represents Hercules as sailing in a boat formed of the hide of a lion, and translates ships to the skies, where they still figure among the constellations. Fable makes Atlas claim the invention of the oar, and gives to Tiphys, the pilot of the Argo, the invention of the rudder. The attributing of these discoveries and improvements to particular individuals doubtless afforded pastime to poets in ages when poetry was more popular than history. Instead of trusting to these fanciful authorities, we may form a very rational theory upon the matter in the following manner:-- Whether it was an insect that floated on a leaf across a rivulet and was stranded on the bank, or a beaver carried down a river upon a log, or a bear borne away upon an iceberg, that first awakened man to the conception of trusting himself fearlessly upon the water, it is highly probable that he learned from animals, whose natural element it is, the manner of supporting his body upon it and of forcing his way through it. A frog darting away from the rim of a pond and striking out with his fore-legs may have suggested swimming, and the beaver floating on a log may have suggested following his example. The log may not have been sufficiently buoyant, and the adventurer may have added to its buoyancy by using his arms and legs. Even to this day the Indians of our own country cross a rapid stream by clasping the trunk of a tree with the left leg and arm and propelling themselves with the right. Thus the first step was taken; and the second was either to place several logs together, thus forming a raft, and raising its sides, or to make use of a tree hollowed out by nature. Many trees grow hollow naturally, such as oaks, limes, beeches, and willows; and it would not require a degree of adaptation beyond the capacity of a savage, to fit them to float and move upon the water. The next step was probably to hollow out by art a sound log, thus imitating the trunk which had been eroded by time and decay. And, in making this step from the sound to the hollow log, the primitive mariners may have been assisted by observing how an empty nut-shell or an inverted tortoise-shell floated upon the water, preserving their inner surface dry and protecting such objects as their size enabled them to carry.