Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/253

 greatest Sensations, as for instance it would be, if we that feel the respirations of a gentle gale, should not feel the impulse of a perpetual winde that beateth upon us with a velocity that runs more than 2529 miles an hour, for so much is the space that the centre of the Earth in its annual motion passeth in an hour upon the circumference of the grand Orb, as he diligently calculates; and because, as he saith, by the judgment of Copernicus, Cum terra movetur circumpositus aër, motus tamen ejus, velocior licet ac rapidior celerrimo quocunque vento, à nobis non sentiretur, sed summa tum tranquilitas reputaretur, nisi alius motus accederet. Quid est verò decipi sensum, nisi hæc esset deceptio? [Which I make to speak to this sense.] The circumposed air is moved with the Earth, yet its motion, although more speedy and rapid than the swiftest wind whatsoever, would not be perceived by us, but then would be thought a great tranquillity, unlesse some other motion should happen; what then is the deception of the sense, if this be not?

It must needs be that this Philosopher thinketh, that that Earth which Copernicus maketh to turn round, together with the ambient air along the circumference of the great Orb, is not that whereon we inhabit, but some other separated from this; for that this of ours carrieth us also along with it with the same velocity, as also the circumjacent air: And what beating of the air can we feel, when we fly with equal speed from that which should accost us? This Gentleman forgot, that we no less than the Earth and air are carried about, and that consequently we are always touch'd by one and the same part of the air, which yet doth not make us feel it.

But I rather think that he did not so think; hear the words which immediatey follow. Præterea nos quoque rotamur ex circumductione terræ &c.

Now I can no longer help nor excuse him; do you plead for him and bring him off, Simplicius.

I cannot thus upon the sudden think of an excuse that pleaseth me.

Go to; take this whole night to think on it, and defend him to morrow; in the mean time let us hear some other of his objections.

He prosecuteth the same Objection, shewing, that in the way of Copernicus, a man must deny his own senses. For that this principle whereby we turn round with the Earth, either is intrinsick to us, or external; that is, a rapture of that Earth; and if it be this second, we not feeling any such rapture, it must be confessed that the sense of feeling, doth not feel its own object touching it, nor its impression on the sensible part: but if the prin-