Page:Micrographia - or some physiological descriptions of minute bodies made by magnifying glasses with observations and inquiries thereupon.djvu/68

Rh the motion upwards, the side A will be deprest to E, and therefore C being thrust to G and D to H; the globular Figure by this means also will be made an Elliptico-spherical. Next if a fluid be included partly with one, and partly with another fluid, it will be found to be shaped diversly, according to the proportion of the gravity and incongruity of the 3 fluids one to another: As in the second Figure, let the upper M M M be Air, the middle L M N O be common Oyl, the lower O O O be Water, the Oyl will be form'd, not into a spherical Figure, such as is represented by the pricked Line, but into such a Figure as L M N O, whose side L M N will be of a flatter Elliptical Figure, by reason of the great disproportion between the Gravity of Oyl and Air, and the side L O M of a rounder, because of the smaller difference between the weight of Oyl and Water. Lastly, The globular Figure will be changed, if the ambient be partly fluid and partly solid. And here the termination of the incompassed fluid towards the incompassing is shap'd according to the proportion of the congruity or incongruity of the fluids to the solids, and of the gravity and incongruity of the fluids one to another. As suppose the subjacent medium that hinders an included fluids descent, be a solid, as let K I, in the fourth Figure, represent the smooth superficies of a Table; E G F H, a parcel of running Mercury; the side G F H will be more flatted, according to the proportion of the incongruity of the Mercury and Air to the Wood, and of the gravity of Mercury and Air one to another; The side G E H will likewise be a little more deprest by reason the subjacent parts are now at rest, which were before in motion.

Or further in the third figure, let A I L D represent an including solid medium of a cylindrical shape (as suppose a small Glass Jar) Let F G E M M represent a contain'd fluid, as water; this towards the bottom and sides, is figured according to the concavity of the Glass: But its upper Surface, (which by reason of its gravity, (not considering at all the Air above it, and so neither the congruity or incongruity of either of them to the Glass) should be terminated by part of a Sphere whose diameter should be the same with that of the earth, which to our sense would appear a straight Line, as F G E, Or which by reason of its having a greater congruity to Glass than Air has, (not considering its Gravity) would be thrust into a concave Sphere, as C H B, whose diameter would be the same with that of the concavity of the Vessel:) Its upper Surface, I say, by reason of its having a greater gravity then the Air, and having likewise a greater congruity to Glass then the Air has, is terminated, by a concave Elliptico-spherical Figure, as C K B. For by its congruity it easily conforms it self, and adheres to the Glass, and constitutes as it were one containing body with it, and therefore should thrust the contained Air on that side it touches it, into a spherical Figure, as B H C, but the motion of Gravity depressing a little the Corners B and C, reduces it into the aforesaid Figure C K B. Now that it is the greater congruity of one of the two contiguous fluids, then of the other, to the containing solid, that causes the separating surfaces to be thus or thus figured: And that it is not because this or that figurated surface is more proper, natural, or peculiar to Rh