Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/409

 and sport with our Fancies) hath, I say, hath permitted that the motions for every other respect, except to resolve the ebbing and flowing of the Sea, assigned long since to the earth, should be found now at last to answer exactly to the cause thereof; and, as it were, with mutual a emulation, the said ebbing and flowing to appear in confirmation of the Terrestrial motion: the judices whereof have hitherto been taken from the cœlestial Phænomena, in regard that of those things that happen on Earth, not any one was of force to prove one opinion more than another, as we already have at large proved, by shewing that all the terrene occurrences upon which the stability of the Earth and mobility of the Sun and Firmament is commonly inferred, are to seem to us performed in the same manner, though we supposed the mobility of the Earth, and the immobility of them. The Element of Water onely, as being most vast, and which is not annexed and concatenated to the Terrestrial Globe as all its other solid parts are; yea, rather which by reason of its fluidity remaineth apart sui juris, and free, is to be ranked amongst those sublunary things, from which we may collect some hinte and intimation of what the Earth doth in relation to motion and rest. After I had many and many a time examined with my self the effects and accidents, partly seen and partly understood from others, that are to be observed in the motions of waters: and moreover read and heard the great vanities produced by many, as the causes of those accidents, I have been induced upon no slight reasons to omit these two conclusions (having made withal the necessary presupposals) that in case the terrestrial Globe be immoveable, the flux and reflux of the Sea cannot be natural; and that, in case those motions be conferred upon the said Globe, which have been long since assigned to it, it is necessary that the Sea be subject to ebbing and flowing, according to all that which we observe to happen in the same.

The Proposition is very considerable, as well for it self as for what followeth upon the same by way of consequence, so that I shall the more intensly hearken to the explanation and confirmation of it.

Because in natural questions, of which number this which we have in hand is one, the knowledge of the effects is a means to guide us to the investigation and discovery of the causes, and without which we should walk in the dark, nay with more uncertainty, for that we know not whither we would go, whereas the blind, at least, know where they desire to arrive; therefore first of all it is necessary to know the effects whereof we enquire the causes: of which effects you, Sagredus, ought more abundantly and more certainly to be informed than I am,