From the quick consecutions of these two, one after another, between the Object and your eye, caused by their motion upwards or downwards, proceeding from their levity or gravity, or to the right or left, proceeding from the wind, a Starr may appear, now bigger, now less, then really it would otherwise without them; and this is that property of a Starr, which is commonly call’d twinkling, or scintillation. The reason why a Star will now appear of one colour, now of another, which for the most part happens when ’tis neer the Horizon, may very easily be deduc’d from its appearing now in the middle of the vapour, other whiles neer the edge; for if you look against the body of a Starr with a _Telescope_ that has a pretty deep _Convex_ Eye-glass, and so order it, that the Star may appear sometimes in one place, and sometimes in another of it; you may perceive this or that particular colour to be predominant in the apparent Figure of the Starr, according as it is more or less remote from the middle of the _Lens_. This I had here further explain’d, but that it does more properly belong to another place. I shall therefore onely add some few Quæries, which the consideration of these particulars hinted, and so finish this Section. And the first I shall propound is, Whether there may not be made an artificial transparent body of an exact Globular Figure that shall so inflect or refract all the Rays, that, coming from one point, fall upon any _Hemisphere_ of it; that every one of them may meet on the opposite side, and cross one another exactly in a point; and that it may do the like also with all the Rays that, coming from a _lateral_ point, fall upon any other _Hemisphere_; for if so, there were to be hoped a perfection of _Dioptricks_, and a transmigration into heaven, even whil’st we remain here upon earth in the flesh, and a descending or penetrating into the center and innermost recesses of the earth, and all earthly bodies; nay, it would open not onely a cranney, but a large window (as I may so speak) into the Shop of Nature, whereby we might be enabled to see both the tools and operators, and the very manner of the operation it self of Nature; this, could it be effected, would as farr surpass all other kind of perspectives as the vast extent of Heaven does the small point of the Earth, which distance it would immediately remove, and unite them, as ’twere, into one, at least, that there should appear no more distance between them then the length of the Tube, into the ends of which these Glasses should be inserted: Now, whether this may not be effected with parcels of Glass of several densities, I have sometimes proceeded so farr as to doubt (though in truth, as to the general, I have wholly despair’d of it) for I have often observ’d in Optical Glasses a very great variety of the parts, which are commonly called Veins; nay, some of them round enough (for they are for the most part, drawn out into strings) to constitute a kind of _lens_.