proposed doubt, I should have contented my self with that only, which is demonstrated by _Archimedes_, in his first _Book De Insidentibus humido_[14]: where in generall termes he infers and confirms the same Conclusions, namely, that Solids (_a_) less grave than water, swim or float upon it, the (_b_) more grave go to the Bottom, and the (_c_) equally grave rest indifferently in all places, yea, though they should be wholly under water. [14] _Of Natation_ (a) _Lib. 1, Prop. 4._ (b) _Id. Lib. 1. Prop. 3._ (c) _Id. Lib. 1. Prop. 3._ [Sidenote: The Authors defence of _Archimedes_ his Doctrine, against the oppositions of _Buonamico_.] But, because that this Doctrine of Archimedes, perused, transcribed and examined by _Signor Francesco Buonamico_, in his _fifth Book of Motion, Chap. 29_, and afterwards by him confuted, might by the Authority of so renowned, and famous a Philosopher, be rendered dubious, and suspected of falsity; I have judged it necessary to defend it, if I am able so to do, and to clear _Archimedes_, from those censures, with which he appeareth to be charged. _Buonamico_ rejecteth the Doctrine of _Archimedes_, first[15], as not consentaneous with the Opinion of _Aristotle_, adding, that it was a strange thing to him, that the Water should exceed the Earth in Gravity[16], seeing on the contrary, that the Gravity of water, increaseth, by means of the participation of Earth. And he subjoyns presently after[17], that he was not satisfied with the Reasons of _Archimedes_, as not being able with that Doctrine, to assign the cause whence it comes, that a Boat and a Vessell, which otherwise, floats above the water, doth sink to the Bottom, if once it be filled with water; that by reason of the equality of Gravity, between the water within it, and the other water without, it should stay a top; but yet, nevertheless, we see it to go to the Bottom. [15] His first Objection against the Doctrine of _Archimedes_. [16] His Second Objection. [17] His third Objection.