Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/173

This page has been proofread, but needs to be validated.
148
G. Galilæus, his Systeme.

alledged. For these birds which at their pleasure flie forwards and backwards, and wind to and again in a thousand fashions, and, which more importeth, lie whole hours upon the wing, these I say do not a little pose me, nor do I see, how amongst so many circumgyrations, they should not lose the motion of the Earth, and how they should be able to keep pace with so great a velocity as that which they so far exceed with their flight.

Salv.To speak the truth, your scruple is not without reason, and its possible Copernicus himself could not find an answer for it, that was to himself entirely satisfactory; and therefore haply past it over in silence; albeit he was, indeed, very brief in examining the other allegations of his adversaries, I believe through his height of wit, placed on greater aud sublimer contemplations, like as Lions are not much moved at the barking of little Dogs. We will therefore reserve the instance of birds to the last place, and for the present, see if we can give Simplicius satisfaction in the others, by shewing him in our wonted manner, that he himself hath their answers at hand, though upon first thoughts he doth not discover them. And to begin with the shots made at randome, with the self same piece, powder, and ball, the one towards the East, the other towards the West (if the diurnal conversion belonged to the Earth) ought to be much longer than that towards the East.

Simpl.I am moved so to think; because in the shot made towards the East,The reason why a Gun should seem to carry farther towards the West than towards the East. the ball whil'st it is out of the piece, is followed by the said piece, the which being carried round by the Earth, runneth also with much velocity towards the same part, whereupon the fall of the ball to the ground, cometh to be but little distant from the piece. On the contrary in the shot towards the West, before that the ball falleth to the ground, the piece is retired very far towards the East, by which means the space between the ball and the piece, that is Range, will appear longer than the other, by how much the piece, that is the Earth, had run in the time that both the bals were in the air.

Salv.I could wish, that we did know some way to make an experiment corresponding to the motion of these projects, as that of the ship doth to the motion of things perpendicularly falling from on high; and I am thinking how it may be done.

Sagr.I believe, that it would be a very opposite proof, to take an open Chariot,The experiment of a running chariot to find out the difference of Ranges. and to accomodate therein a ** Balestrone da bolzoni. Stock-bow at half elevation, to the end the flight may prove the greatest that my be, and whil'st the horses shall run, to shoot first towards the part whither you drive, and then another backwards towards the contrary part, causing some one to mark diligently where the Chariot was in that moment f time when the shaft came to

the