It would certainly, I replied be more in character, to trace only the footsteps of lovers; that is to say, your name, engraved by your adorers on the bark of every tree. No more of adorers, cried she; let us talk of the sun. I understand perfectly why we imagined it performing the revolution which is merely effected by our own motion, but this circle requires a year; how, then, does the sun appear to go round us every day? You undoubtedly know, I replied, that if a ball were rolled along this walk it would have two sorts of motion; it would go towards the end of the walk, and at the same time turn several times on its own axis, so that the side of the ball which is at first uppermost will presently descend, and the other, of course, rise to the top. This is the case with the earth: whilst she is proceeding, through the year, in her orbit round the sun, she turns on her own axis every twenty-four hours: each part, therefore, of the earth loses, and recovers sight of the sun during that time. When in the morning we turn towards the sun, it seems to rise; and when, by continued rotation, we again are more distant from it, it appears to descend. That's curious enough, said she; the earth undertakes every thing, and the sun does nothing at all: and when the moon, the other planets, and the fixed stars appear to pass over us in four-and-twenty hours, it is merely imagination. Exactly so, I replied, and produced by the same cause. The planets perform their revolutions round the sun in unequal periods of time, in consequence of their different distances from it; and one which we see to day answer to a certain point in the zodiac, or circle of fixed stars, will to-morrow at the same hour answer to some other point: this is the effect both of the progress which the planet has made in its orbit and of that which we have made in ours. We move onward; the other planets do the same, but we do not continue all in a line: this occasions us to see them in such different situations, and renders their course apparently irregular. You now understand that such irregularity depends only on the different points from which we view them, and that, in reality all their movements are directed by the most exact order. It may be so, answered the Marchioness; but I should be glad if their order did not cost the earth so much: you seem to have very little consideration for it, and to require an astonishing agility in so large a body. But, said I, do you think it more reasonable for the sun, and all the other heavenly bodies, which are extremely large, to perform in four-and-twenty hours an immense journey round the earth? That the fixed stars, being in the largest circle, should travel, in the course of a day, more than twenty-seven thousand six hundred and sixty times two hundred millions of leagues?[11] All this must be if the earth does not turn on her axis every twenty-four hours. Surely there is much more rationality in supposing our globe to turn, which