OF THE MENSURATION OF Running Waters.

LIB. I.

What, and of how great moment the confideration of Motion is in natural things, is so manifest, that the Prince of Peripateticks pronounced that in his Schools now much used Sentence: Ignorato motu, ignoratur natura. Thence it is that true Philosophers have so travailed in the contemplation of the Celestial motions, and in the speculation of the motions of Animals, that they have arrived to a wonderful height and sublimity of understanding. Under the same Science of Motionis comprehended all that which is written by Mechanitians concerning Engines moving of themselves, Machins moving by the force of Air, and those which serve to move weights and immense magnitudes with small force. There appertaineth to the Science of Motion all that which hath been written of the alteration not onely of Bodies, but of our Minds also; and in sum, this ample matter of Motion is so extended and dilated, that there are few things which fall under mans notice, which are not conjoyned with Motion, or at least depending thereupon, or to the knowledge thereof directed; and of almost every of them, there hath been written and composed by sublime wits, learned Treatises and Instructions. Bbbb And