I. _Hydrostatical Paradoxes, made out by New Experiments (for the most part Physical, and Easie) by the Honourable Robert Boyle._ This Treatise, promised in _Numb._ 8. of these Papers, is now come forth: And was occasioned by the perusal of the Learned Monsieur _Paschalls_ Tract, _Of the AEquilibrium of Liquors_, and of the _Weight of the Air_: Of which two Subjects, the _latter_ having been more clearly made out in _England_ by Experiments, which could not be made by Monsieur _Paschal_ and others, that wanted the advantage of such Engines and Instruments, as have here been frequently made use {174} off; Our Noble Author insists most upon giving us his thoughts of the former, _videl._ the _AEquilibrium of Liquors_: Which Discourse consisting partly of _Conclusions_, and partly of _Experiments_, the _former_ seem to Him to be almost all of them consonant to the Principles and Laws of the _Hydrostaticks_; but as for the _latter_, the Experimental proofs, offered by M. _Paschall_ for his Opinions, are by our Author esteemed such, that he confesses, he hath no mind to make use of them: for which he alledges more reasons than one; which, doubtless, will appear very satisfactory to Intelligent _Readers_. Wherefore, instead of the those _Paschalian_ Experiments, there is in this _Treatise_ deliver'd a far more Expeditious way, to make out, _not only_ most of the _Conclusions_, agreed on these two Authors, _but_ others also, that M _Paschall_ mentions not: and that with so much more ease and clearness, that persons, but ordinarily versed in the common principles of _Hydrostaticks_, may readily apprehend, what is deliver'd, if they will but bring with them a due Attention, and Minds disposed to prefer Reason and Experience to Vulgar opinions and Authors. It not being our _Authors_ present Task, to deliver a Body of _Hydrostaticks_, but only some _Paradoxes_, which he conceives to be proveable by his New way of making them out, he delivers them in as many distinct Propositions; after each of which, he endeavours, in a Proof, or an Explication, to show, both that it is true, and why it ought to be so. The _Paradoxes_ themselves (after a premised _Postulatum_) are these: 1. That in Water, and other Fluids, the Lower parts are pressed by the Upper. 2. That a lighter Fluid may gravitate or weigh upon a heavier. 3. That, if a Body, contiguous to the Water, be altogether, or in part, lower than the highest level of the said Water, the lower part of the Body will be pressed upward by the Water, that touches it beneath. 4. That in the Ascension of Water in Pumps, &c. there needs nothing to raise the Water, but a Competent weight of an External Fluid. 5. That the pressure of an External Fluid is able to keep an Heterogeneous Liquor suspended at the same height in several Pipes, though these Pipes be of very different Diameters. {175}