_Secondly_, Whereas the _French_ Author is of opinion, that 'tis unknown, how much time a Heavy Body requires to sink in water, according to a certain depth; he may please to take notice, that that hath been made out in _England_ by frequent Experiments; by which, several Depths, found by this Method of sounding _without_ a Line, were examin'd by trying them over again in _the same_ place _with_ a Line, after the common way. And as to that _Quaere_ of his, Whether a heavy Body descends in the same _Proportion_ of swiftness in _Water_, that it would do in _Air_? The Answer is, that it does not; but that, after it is sunk one or two fathoms into the Water, it has there arrived to its greatest swiftness, and keeps, after that, an equal degree of velocity; the _Resistance_ of the water being then found equal to the _Endeavour_ of the heavy Body downwards. _Thirdly_, When the same _Author_ alledges that it must be known, when a Light Body reascends from the bottom of the water to {230} the top, in what proportion of time and swiftness it rises. He seems not to have considered, that in this Experiment, the times of the descent and assent are both taken and computed together; so that for this purpose, there needs not that nicety, he discourses of. _Fourthly_, Whereas it is further excepted, That this way of Sounding Depths is no new Invention; The answer is ready, that neither is it pretended to be so, in the often quoted _Tract_; it being only intimated there, that the manner of performing it, as it is in that place represented and described, is new. _Lastly_, To rectifie the said Author's mistake, as if the instrument of fetching up Water from the bottom of the Sea, were chiefly contriv'd, to find out, Whether in some places of the Sea any _Sweet_ Water is to be met with at the bottom: There will need no more, than to direct him to the Book it self _Num._ 9. where p. 149. towards the end, the _First_ use of this _Bucket_ is express'd to be, to know the _degrees of Saltness_ of the Water according to its nearness to the top or bottom; or rather to know the constitution of the Sea-water in several depths of several _Climates_, which is a matter, much better to be found out by _Trial_, than _Discourse_. Neither is it any where argued in that Book (as the _French Journal_ insinuates) that, because sweet water is found at the Bottom of the Sea of _Baharem_, therefore it _must_, but only that it _may_, be found so elsewhere. And since the same _Journal_ admits, that those Sweet water-springs, which yield the sweet water, that is found at the said place, have been formerly on the _Continent_, far enough from the Sea, which hath afterwards covered them. It will be, it is presumed, lawful to ask, Why in many other places there may not be found the like? And besides, how we do know, but that there may be in other parts, Eruptious of large Springs at the bottom of the Sea, as well as there? * * * * *