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 ALIORUM FLUMINUM ORIGINE_. It was _Numb._ 14. 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 {305} by this means rises above its Levell, yet it does never run out at the top of the Pipe. Having said this, he answers to the other Arguments, commonly alledged to maintain this Opinion.