Page:Philosophical Transactions - Volume 001.djvu/317

 indeed that very Comet, which he saw with his naked Eye, and observed with his Geometrical Instruments, the said 12, 13, and 14. dayes of February; or whether it was another, and whether he had lost that Comet, which moved towards the Second Star in Aries: but leaves it to the Learned World, and particularly to the Royal Society, after they shall have well examined and considered all his Observations, and the Calculus raised therefrom, to judge of this, and the other particulars in controversie.

II. Isaacus Vossius de NILI et ALOIRUM FLUMINUM ORIGINE. It was of these Transactions, that gave an account of the Cause of the Inundation of the Nile, as it was rendred by Monsieur de la Chambre: This is to give you another, not only of the Inundation, but also of the Origine of that, and of other Rivers, as it is delivered by Monsieur Isaac Vossius, who undertakes in this Book to shew;

1. That those Subterraneous Channels, through which several Philosophers teach, that the Sea discharges it self into the Rivers, are not only imaginary, but useless, in regard 'tis impossible for the water to rise from the Subterraneous places up to the Mountains, where commonly the Sources of Rivers are.

2. He explicates, why, if a Pipe be put into a Bason full of Water, the water is seen more raised in the Pipe, than in the Bason, and rises higher according as the Pipe is narrower, On the contrary, if the same Pipe be put into a Bason full of Quicksilver, the Quicksilver stayes lower in the Pipe, than in the Bason. The reason, which he renders hereof, is, That as the Water sticks easily to all it touches, it is sustain'd by the sides of the narrow Pipe wherein it is included: And indeed, if the Pipe be quite drawn out of the Water, the Water doth not all fall out, but so much of it remains, as the sides of the Pipe could sustaine: Whence it is, that the Water which is kept up by the Walls of the Tube, weighing no longer upon that which is in the Bason, is thrust upwards, and keeps it self raised above its Levell; but the Quicksilver not adhering so easily, as Water, to Bodies it touches, is not sustained by the sides of the Tube, and so mounts not above its Levell, but rather descends below it, because the Pipe, which is streight, hinders the endeavor that is in the Mercury to rise to its Level. He adds, that this Observation makes nothing for the Explication of the Origine of Rivers; because, though it be true, that the Water Rh