concerning which art, it is commonly thought that these men direct their aims to some certain space in the air, just before the birds, where they conceive the bullet will meet with them in their flight; whereas the truth is, they proceed in this case, the very same way, as if the birds did stand still, by a direct aiming at their bodies, and following of their flight by the motion of the piece, till at length, having got a perfect aim, they discharge, and do hit altogether as surely, as if the birds were sitting upon a tree. From whence we may observe, that the motion of the piece, as in our aiming it is made to follow the birds in their flight (though it be but slow,) yet is communicated to the bullet in the air.

But here it may seem very difficult to give any reason according to those grounds concerning the flight of birds; which being animated, have a liberty to fly here or there, to tarry for a good space of time in the open air, and so it is not easy to conceive what means there is, by which they should participate of the earth's diurnal revolution.

To this Galilæus answers, that the motion of the air, as it does turn about the clouds, so doth it also carry with it the birds, together with such other like things that are in it. For if some violent wind be able to drive with such swiftness a full laden ship, to throw down towers, to turn up trees, and the like; much more then may the diurnal motion of the air, (which does so far exceed in swiftness the most tempestuous wind) be able to carry with it the bodies of birds.

But if all things be turned about by this revolution, then it should seem there is no such thing as a right motion, whether of ascent, or descent in a strait line.

I answer; the moving of heavy or light bodies, may be considered in a double relation.

1. According to the space wherein they move, and we grant their motions not to be simple, but mixed of a direct and circular.

2. According to the body or medium wherein they move, and then they may properly be said to have right

motions, because they pass through the medium in a strait line; and therefore it is, that unto us they seem directly to ascend or descend. Aristotle himself would not deny, but that fire may ascend in a strait line unto its sphere; and yet participate also of that circular motion which he supposes to be communicated from the heaven, unto the upper part of the air, and its own region. So likewise must it be for the descent of any thing. Suppose a ship in its swiftest motion, and a man in it, having some vessel filled with water, should let fall into it a little ball of wax, or some other matter which may be slow in its sinking, so that in one minute it should scarce descend the space of a cubit, though the ship (it may be) in the same time may pass at least a hundred cubits; yet would this still seem unto the eye to descend in a strait line; and the other motion which is communicated unto it by the ship, would not at all be discernible in it. And though in this case, the motion were in itself composed of a circular and direct; yet in respect of us it would appear, and so might be stiled, exactly strait.

Now if it be thus in those which are generally granted to be preternatural motions; we need not doubt then the possibility of the like effect in that motion which we conceive to be proper and natural, both to the earth, and the things that belong unto it.

There is yet another objection to this purpose urged by Malapertius*, a late jesuit; who, though he do with much eagerness press this argument concerning a bullet or stone, against the opinion of Copernicus; yet he grants that it might easily be resolved, if the defenders of it would affirm that the air did move round with the earth. But this, says he, they dare not avouch; for then the comets would always seem to stand still, being carried about with the revolution of this air; and then they could not rise or set, as experience shews they do.

To this it may be answered, that most comets are above

that sphere of air which is turned round with our earth, as is manifest by their height. The motion that appears in them, is caused by the revolution of our earth, whereby we are turned from them.

As for those which are within the orb of our air, these do seem to stand still. Such a one was that mentioned by Josephus*, which did constantly hang over Jerusalem; and that likewise which appeared about the time of Agrippa's death, and for many days together did hang over the city of Rome. Wherefore Seneca + does well distinguish out of Epigenes, betwixt two sorts of comets; the one being low, and such as seem immoveable; the other higher, and such as did constantly observe their risings and settings, as the stars.

I have done with all the arguments of any note or difficulty, that are urged against this diurnal motion of the earth. Many other cavils there are, not worth the naming, which discover themselves to be rather the objections of a captious, than a doubtful mind. Amongst which, I might justly pass over those that are set down by Alex. Rosse ‡. But because this author does proceed in his whole discourse with so much scorn and triumph, it will not be amiss therefore to examine what infallible evidence there is in those arguments upon which he grounds his boastings.

We have in one chapter no less than these nine.

1. If the earth did move, then would it be hotter than the water, because motion does produce heat: and for this reason likewise, the water would be so hot and rarified, that it could not be congealed; since that also does partake of the same motion with the earth.

2. The air which is next the earth, would be purer, as being rarified with motion.

3. If the earth did move the air, it would cause some sound; but this is no more audible, than Pythagoras's harmony of the heavens.

De bello Judaico, 1. 7. cap. 12. Dion. 1. 54.

† Nat. Qu. lib. 7. cap. 6.

Lib. 1. sect. 2. cap. 6.

4. It would have been in vain for nature to have endowed the heavens with all conditions requisite for motion, if they had been to stand still. As first, they have a round figure. Secondly, they have neither gravity nor levity. Thirdly, they are incorruptible. Fourthly, they have no contrary.

5. All similary parts are of the same nature with the whole: but each part of the earth does rest in its place; therefore also doth the whole.

6. The sun in the world is as the heart in a man's body; but the motion of the heart ceasing, none of the members do stir: therefore also if the sun should stand still, the other parts of the world would be without motion.

7. The sun and heavens do work upon these inferior bodies by their light and motion. So the moon does operate upon the sea.

8. The earth is the foundation of buildings, and therefore must be firm and stable.

9. It is the constant opinion of divines, that the heavens shall rest after the day of judgment; which they prove from Isa. vi. 20. Thy sun shall no more go down, neither shall thy moon withdraw itself. So likewise, Rev. x. 6. The angel swears that there shall be time no longer; and therefore the heavens must rest, since by their motion it is that time is measured. And St. Paul says, Rom. viii. 20. That all the creatures are subject to vanity. Now this can be no other in the heavens, than the vanity of motion, which the wise man speaks of, Eccles. i. 4. The sun riseth, and the sun goeth down, &c.

To these it may be answered:

In the first you may note a manifest contradiction, when he will have the earth to be hotter than the water, by reason of this motion; when as notwithstanding, he acknowledges the water to move along with it: and therefore too in the next line, he infers that the water, because of that heat and rarefaction which it receives from this motion with the earth, must be incapable of so much cold, as to be congealed into ice.

But unto that which may be conceived to be his meaning in this and the next argument; I answer: if he had fully understood this opinion which he opposes, he would easily have apprehended that it could not be prejudiced by either of these consequences. For we suppose that not only this globe of earth and water, but also all the vaporous air which environs it, are carried along by the same motion. And therefore, though what he says concerning the heat; which would be produced by such a motion, were true, yet it would not be pertinent, since our earth and water, and the air next unto them, are not by this means severed from one another, and so do not come within the compass of this argument.

If any reply, that this will notwithstanding hold true concerning the upper part of the air, where there is such a separation of one body from another; and so consequently, an answerable heat. I answer,

1. It is not generally granted, that motion in all kind of bodies does produce heat; some restrain it only to solid bodies, affirming, that in those which are fluid, it is rather the cause of coldness. This is the reason, say they, why running waters are ever to our sense the coolest; and why, amongst those winds which proceed from the same coasts of heaven, about the same time of the year, the strongest always is the coldest? If you object, that running waters are not so soon frozen as others, they answer; this is not because they are thereby heated, but because unto congelation it is requisite that a body should settle and rest, as well as be cold.

2. If we should grant a moderate heat in those parts of the air, we have not any experiment to the contrary, nor would it prejudice the present opinion, or common prin ciples.

As the sound of this motion is not more heard than the harmony of the heavens; so neither is there any reason why this motion should cause a sound, more than the supposed motion of the heavens, which is likewise thought to be continued unto the air hard by us.