Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/404

 reason for the introducing of it: If by plucking away a piece of Loadstone from the whole natural masse, it were deprived of the faculty of following it, as it did, whilst it was united thereto, so that it is thereby deprived of the revolution about the universal centre of the Terrestrial Globe, it might haply, with somewhat greater probability be thought by some, that the said Magnet was to appropriate to it self a new conversion about its particular centre; but if it do no lesse, when separated, than when conjoyned, continue always to pursue its first, eternal, and natural course, to what purpose should we go about to obtrude upon it another new one?

I understand you very well, and this puts me in mind of a Discourse very like to this for the vanity of it, falling from certain Writers upon the Sphere, and I think, if I well remember, amongst others from Sacrobosco, who, to shew how the Element of Water, doth, together with the Earth, make a compleat Spherical Figure, and so between them both compose this our Globe, writeth, that the seeing the small * particles of water shape themselves into rotundity, as in the drops, and in the dew daily apparent upon the leaves of several herbs, is a strong argument; and because, according to the trite Axiome, there is the same reason for the whole, as for the parts, the parts affecting that same figure, it is necessary that the same is proper to the whole Element: and truth is, methinks it is a great oversight that these men should not perceive so apparent a vanity, and consider that if their argument had run right, it would have followed, that not only the small drops, but that any whatsoever greater quantity of water separated from the whole Element, should be reduced into a Globe: Which is not seen to happen; though indeed the Senses may see, and the Understanding perceive that the Element of Water loving to form it self into a Spherical Figure about the common centre of gravity, to which all grave bodies tend (that is, the centre of the Terrestrial Globe) it therein is followed by all its parts, according to the Axiome; so that all the surfaces of Seas, Lakes, Pools, and in a word, of all the parts of Waters conteined in vessels, distend themselves into a Spherical Figure, but that Figure is an arch of that Sphere that hath for its centre the centre of the Terrestrial Globe, and do not make particular Spheres of themselves.

The errour indeed is childish; and if it had been onely the single mistake of Sacrobosco, I would easily have allowed him in it; but to pardon it also to his Commentators, and to other famous men, and even to Ptolomy