Through the Earth/Chapter XXII
THE NEW MOHAMMED
HE situation was indeed a strange one. Here was our hero, in full possession of all his powers, suspended in mid-air, and seemingly absolutely powerless to budge a single inch in any direction; for it is one of the first laws in physics that a body cannot be set in motion without the action of some force, and no force is possible without some point of resistance against which to act.
"Well, here's a pretty state of thing's!" exclaimed William, dolefully. "Dr. Giles must have overlooked the fact that I'm to be kept prisoner up here. It's no earthly use my trying to reach the bottom of the car, because I have no means whatever of moving from this spot. If there were only somebody else in the car, he could throw a chair or something at me, and so knock me close enough to the wall to enable me to catch hold of one of the straps; but there being nobody with me, there seems no possible means of my reaching the floor."
It was indeed an awkward predicament, and the more William puzzled over the problem, the more difficult did it appear, until finally an idea struck him.
"If I only had a heavy weight here with me," said he, "I could reach the side of the car fast enough; for by throwing the weight with all my force toward one side of the car, the reaction would be sufficient to push me in the opposite direction. Unfortunately, the heaviest thing I have in my pockets is my jack-knife, and that is much too light for the purpose. I could, of course, cut off one of my arms and use that for a weight. By throwing it in any direction my body would certainly be pushed back in the opposite direction until I reached the walls of the car; and once I could get hold of the straps, I should be all right. This method would be sure to succeed, but it's one I should wish to be excused from trying."
William's theory, singular though it may appear, was nevertheless perfectly correct. The mere act of throwing a heavy body in any direction would have sufficed to set his own body traveling in the opposite direction. Of course the speed at which he would move would depend upon the weight of the body thrown, or rather upon its mass, since bodies in the car no longer possessed weight.
In other words, supposing some emergency to arise which would render it absolutely necessary for our hero to reach the side of the car, he could do this by resorting to the heroic expedient of cutting off his own arm and hurling it away from him with all his strength. A singular expedient, truly, but a most effective one; for, assuming his arm to be one tenth as heavy as the rest of his body, he would move in one direction with one tenth of the speed at which his arm was thrown in the opposite direction.
"It's some comfort," thought William, as he meditated over this curious plan, "to know that I could, if I wanted, reach the side of the car; but at present I hardly think it worth while to sacrifice one of my arms for no real advantage. If ever I get out of this fix alive, I want both my arms to come out with me. If only my jack-knife were a little heavier I could make that answer, but I'm afraid it's much too light."
The idea of utilizing the knife in this way seemed, however, to haunt him, and at last he exclaimed:
"I don't see why the knife won't answer almost as well as my arm. Being so light, the reaction will, of course, be much less, and it will consequently take me a great deal longer to reach the side of the car.
"Let me see; the calculation is an easy one to make. My knife weighs about one ounce, and my body weighs over one hundred pounds. Consequently, if I throw the knife with sufficient force to make it reach one side of the car in a single second, the reaction will force my body to the other side of the car in sixteen hundred seconds, that is to say, about twenty-six minutes. In other words, I shall not be obliged to remain suspended here more than half an hour, at the most. That's bad enough, I must confess, but it might have been worse."
Just as William was about to throw the knife, a new thought stayed his hand. "I forgot the resistance of the air!" he exclaimed. "The knife will pass through the air all right, because it is small; but my body is so large that the air will stop me before I get half-way to the side of the car!"
Our hero's face fell; but the idea of the resistance of the air suggested a new train of thought.
"Hurrah!" he cried. "I see now how I shall be able to reach the side of the car! All that I have been saying about being obliged to stay here would be true only if there were no air in the car. If there were no air I should indeed have no point of resistance against which to work. But there is air in the car, and this will prove my salvation. The air in the car will furnish me with the point of resistance I have been seeking. In five minutes I shall reach the floor, for I will swim down through the air! It will be harder work to swim here than through water, but it will be far better than to remain suspended in mid-air like this!"