The fallacy here may be easily pointed out. A ship is driven through water by a body in motion, namely, wind, while its rudder is dragged through a body comparatively at rest, namely, water; hence the rudder slides against or is pushed against the water, and according as it is _turned_ to one side or the other, it is _pushed_ to one side or the other, the stern of the ship going along with it, and the bow, of course, making a corresponding motion in the opposite direction. Thus the ship is turned or "steered," but it is manifest that if the ship were at rest there would be no pushing of the rudder by the water--no steering. On the other hand, if, though the ship were in motion, the sea was also flowing at the _same rate_ with the wind, there would be no flowing of water past the ship, the rudder would not be acted on, and the vessel could not be steered. Now a balloon, carried by the wind, cannot be steered by a rudder, because it does not, like the ship, rest half in one medium which is in motion, and half in another medium which is at rest. There is no sliding of any substance past its side, no possibility therefore of pushing a rudder against anything. All floats along _with_ the wind. If, however, the balloon could be made to go _faster_ than the wind, then steering would at once become possible; but sails cannot accomplish this, because, although wind can drive a ship faster than water flows, wind cannot drive a substance faster than itself flows. The men of old did not, however, seem to take these points into consideration. It yet remains to be seen whether steam shall ever be successfully applied to aerial machines, but this may certainly be assumed in the meantime, that, until by some means a balloon is propelled _faster than the wind_ through the atmosphere, sails will be useless, and steering, or giving direction, impossible. It was believed, in those early times, when scientific knowledge was slender, that the dew which falls during the night is of celestial origin, shed by the stars, and drawn by the sun, in the heat of the day, back to its native skies. Many people even went the length of asserting that an egg, filled with the morning dew, would, as the day advanced, rise spontaneously into the air. Indeed one man, named Father Laurus, speaks of this as an observed fact, and gravely gives directions how it is to be accomplished. "Take," says he, "a goose's egg, and having filled it with dew gathered fresh in the morning, expose it to the sun during the hottest part of the day, and it will ascend and rest suspended for a few moments." Father Laurus must surely have omitted to add that a goose's brains in the head of the operator was an element essential to the success of the experiment!