But more to your commendation, it seems ye do all these wonders by Magick; for ye have the ordinair principles of none of these Sciences: Euclid is as much a stranger as reason in all your Books: and for this _Perque Mathematicos semper celebrabere fastus_! At last ye come to prove a new doctrine, which before now was near 2000 years old, with thirty new Theorems which must not be named because they are of such a tender and delicat complexion that the very naming of them will make them old. There are also many other excellent things, which will be all new when they were but printed yesterday. It is like some of these dayes, we may have an _Ars Nova et Magna_, to prove that a piece of lead is heavier than so much cork. I know not wherefore ye undervalue any man, because he hath not as great esteem for your notions as yourself: Have not we as much freedom to speak our mind of you, as ye have to write yours of the R. Society and the University of Glasgow? The greatest hurt ye can do us, is to make Dromo famulus one of our Principals. I think it not strange that ye using only demonstrations of sense, should admire the force of our imagination, in affirming no method of Dyving so good as that of Melgin. I am sure that the man Dyving for a continual time, if he be not also of your invention, must breath of the air; and this air must either be kept close by itself, as in Melgin’s way, or communicat with the air above. If the latter be your invention, I doubt ye must also have some Chirurgical invention to apply to your Dyver at his return, if he go to any great deepness: If the former, it is the same with Melgin’s; and you cannot neither any man else help it, but in circumstances (which alters not the method) and perchance to little purpose. As for Archimedes, I am sure he wanted no necessary requisit to prove the weight of water in its own Element. I know not what else ye intend to prove: Always I am as sure that he had two great requisits, which ye want; to wit, Geometry and a sound head. As to what ye write concerning the imperfection of Sciences; the scientifical part of Geography is so perfected, that there is nothing required for the projection, description and situation of a place, which cannot be done and demonstrat. The scientifical part of opticks is so perfected, that nothing can be required for the perfection of sight, which is not demonstrat, albeit men’s hands cannot reach it; and these being the objects of the fore-said Sciences, your authority shall not persuade me that it is altogether improper to call them perfect. In the Hydrostaticks, it were no hard matter to branch out all the experiments that can be made into several Classes, of which the event and reason might perfectly be deduced, as consectaries (I speak not here of long deductions, as ye seem to rant) to something already published: if it be noticed but rudely (as ye, not understanding what niceties of proportion means, must do) only considering Motion and Rest: