The least informed schoolboy, at the present day, would tell him, in answer: "The earth has neither cornerstone nor foundation; and, as to its dimensions, we know them perfectly well, as from Magellan to Bougainville, various navigators have sailed round it." The same schoolboy would put to silence the pompous declaimer Lactantius, and all those who before and since his time have decided that the earth was fixed upon the water, and that there can be no heaven under the earth; and that, consequently, it is both ridiculous and impious to suppose the existence of antipodes. It is curious to observe with what disdain, with what contemptuous pity, Lactantius looks down upon all the philosophers, who, from about four hundred years before his time, had begun to be acquainted with the apparent revolutions of the sun and planets, with the roundness of the earth, and the liquid and yielding nature of the heaven through which the planets revolved in their orbits, etc. He inquires, "by what degrees philosophers attained such excess of folly as to conceive the earth to be a globe, and to surround that globe with heaven." These reasonings are upon a par with those he has adduced on the subject of the sibyls. Our young scholar would address some such language as this to all these consequential doctors: "You are to learn that there are no such things as solid heavens placed one over another, as you have been told; that there are no real circles in which the stars move on a pretended firmament; that the sun is the centre of our planetary world; and that the earth and the planets move round it in space, in orbits not circular but elliptical. You must learn that there is, in fact, neither above nor below, but that the planets and the comets tend all towards the sun, their common centre, and that the sun tends towards them, according to an eternal law of gravitation." Lactantius and his gabbling associates would be perfectly astonished, were the true system of the world thus unfolded to them. HEAVEN OF THE ANCIENTS. Were a silkworm to denominate the small quantity of downy substance surrounding its ball, heaven, it would reason just as correctly as all the ancients, when they applied that term to the atmosphere; which, as M. de Fontenelle has well observed in his "Plurality of Worlds," is the down of our ball. The vapors which rise from our seas and land, and which form the clouds, meteors, and thunder, were supposed, in the early ages of the world, to be the residence of gods. Homer always makes the gods descend in clouds of gold; and hence painters still represent them seated on a cloud. How can any one be seated on water? It was perfectly correct to place the master of the gods more at ease than the rest; he had an eagle to carry him, because the eagle soars higher than the other birds.