“I saw it myself the day we took the trip with you. If one looks out, the road seems to fly back so fast it frightens you and makes you dizzy.”
“The locomotive that drew us went at the rate of about ten leagues an hour. Let us suppose a locomotive that never stops and that goes still faster, or fifteen leagues an hour. Rushing at that speed, the engine would go from one end of France to the other in less than a day; and yet, to cover the distance from the earth to the sun, it would take more than three centuries. For such a journey, the fastest engine ever made by the hand of man is hardly more than a sluggish snail ambitious to make the tour of the world.”
“And I who thought, not long ago,” said Emile, “that by climbing to the roof and with the aid of a long reed I could touch the sun!”
“To one who trusts to appearances the sun is only a dazzling disc, at the most as large as a grindstone.”
“That is what I said yesterday,” observed Jules. “But, as it is so far away, it might well be as large as a millstone.”
“In the first place, the sun is not flat like a grindstone; it has, like the earth, the shape of a ball. Furthermore, it is much larger than a grindstone, or even than a millstone.
“Objects seem to us small in proportion to their distance from us, until finally they become invisible. A high mountain seen from afar seems only a moderate-sized hill; the cross that surmounts a steeple, seen from below, looks very small despite its very large dimensions. It is the same with the sun: it looks so small only because it is very far off; and as the distance is prodigious, its size must be excessive; if not, instead of looking to us like a dazzling grindstone, it would cease to be visible to us.
“You found the terrestrial globe enormous; and, despite my comparisons, your imagination, I am sure, has not been able to picture things properly. How will it be with the sun, which is one million four hundred thousand times as large as the earth! If we suppose the sun hollow like a spherical box, to fill it would take one million four hundred thousand balls the size of the earth.
“Let us try another comparison. To fill the measure of capacity called the liter, it takes about 10,000 grains of wheat. It would take, then, 100,000 to fill 10 liters or one decaliter, and 1,400,000 to fill 14 decaliters. Well, suppose in one pile 14 decaliters of wheat, and beside it one solitary grain of wheat. For the respective sizes, this isolated grain represents the earth; the pile of 14 decaliters represents the sun.”
“How wrong we were!” Claire exclaimed. “This little shining disc, to which, for fear of exaggeration, we should have hesitated to assign the dimensions of a millwheel, is a globe so big that in comparison with its gigantic size the earth is as nothing.”