THE SECOND PART

in truth; for who has ever been there and looked upon such a cavity? To whom I reply: even if there is no eyewitness of this thing, natural Philosophy nevertheless provides sufficient testimony by which such a place is demonstrated to exist in truth. For no one denies that the Sun and the stars circle the earthly globe with their motion and impress their rays upon it. This being granted, which no sane person would contradict, you must also concede that those hot and invisible rays proceed with an innate impetus until they are halted somewhere and prohibited from going further, which occurs in the innermost point of the earth; or else you accuse all philosophers, who believe with unanimous consent that heat is always carried forward and not backward, of lying. Here is an evident example of this thing for you: Place a glowing coal upon some thick plate, whether of iron or copper. When you first feel the lower side warming from the penetrating heat, remove the coal and examine with your hand how much you perceive to be harmed by the excessive heat. Examine also the lower side of the plate, which you will observe to be only slightly warm. After a little delay, examine it again, and you will discover that the heat has progressed, and the plate is hotter below than in the upper part where the coal had rested. Hence, you will clearly see that heat is never carried backward, but always forward. If this is so, you will be forced, willing or unwilling, to admit that the Astral heat similarly does not stick to the surface of the earth but penetrates to the very lowest Center.

You may insist: If the rays of the sun descend through the thickness of the earth to