Page:Popular Science Monthly Volume 22.djvu/793

This page has been proofread, but needs to be validated.

Let us finish our argument with an imaginary illustration embodying the principles and the consequences derived from them. An adventurous explorer, visiting the countries in which Gulliver traveled, brings back a Lilliputian and a Brobdingnagian. The giant is thirty feet high, the dwarf four inches. Since one is about a hundred times as large as the other, their respective masses, and consequently the masses of their muscles, must be in the proportion of a million to one. If a common man weighs sixty kilogrammes, or 150 pounds, the Brobdingnagian should weigh 15,000 kilogrammes, or about 38,000 pounds, and the Lilliputian only fifteen grammes. They agree to compete with each other in the gymnasium. At the pulleys, the Brobdingnagian can easily raise a weight of 10,000 kilogrammes, or 2,500 pounds, as high as his shoulders. Looking to the Lilliputian, we would at first sight not expect him to be able to raise more than ten grammes to his shoulders. Pie really proves able to lift a hundred times as much, or one kilogramme, or the equivalent of seventy-five times his weight. This is because the distance to his shoulders is a hundred times less than the distance to his rival's shoulders, and he is able to apply against the weight the advantage which he derives from the relative shortness of the distance.

They next try leaping at the bar. The Lilliputian gracefully clears the pole at a metre from the ground. Will the Brobdingnagian be able to make a bound of a hundred metres? Not at all. He can hardly clear the bar at five or six metres. This is not because he is lacking in suppleness. Compare his mass with that of his little rival, consider that he has raised the center of gravity of that mass to the height of about a metre as the other has done with that of his inferior mass, and it will not be hard to do justice to his agility.

They are next started on a foot-race. A course of a thousand metres is laid out. The Brobdingnagian runs it in five minutes by steps of four metres each per second. The Lilliputian's steps are only four centimetres each, but he makes a hundred of them in a second; so he likewise goes over the track in five minutes. You give all praise to the Lilliputian, but do an injustice to his competitor. Think of what the giant has to do to move his legs! They are a million times as heavy as the Lilliputian's. But while he may have a million fibers, or a thousand in the diameter of a transverse section, the Lilliputian will have ten fibers in the corresponding diameter, or a thousand in all. Thus, while the masses are in the proportion of a million to one, the proportion as to the motive fibers is a million to a hundred. The Lilliputian, then, has the advantage. It may be objected that a hundred steps can hardly be made in a second. The objection is, however, only specious, for the wings of insects show us what is possible in this matter.

We are authorized by the aid of these illustrations to draw the important conclusion that the minute world is not, and can not be, in all