Observ. LVIII. _Of a new Property in the _Air_, and several other transparent _Mediums_ nam’d _Inflection_, whereby very many considerable _Phænomena_ are attempted to be solv’d, and divers other uses are hinted._ Since the Invention (and perfecting in some measure) of _Telescopes_, it has been observ’d by several, that the Sun and Moon neer the Horizon, are disfigur’d (losing that exactly-smooth terminating circular limb, which they are observ’d to have when situated neerer the Zenith) and are bounded with an edge every way (especially upon the right and left sides) ragged and indented like a Saw: which inequality of their limbs, I have further observ’d, not to remain always the same, but to be continually chang’d by a kind of fluctuating motion, not unlike that of the waves of the Sea, so as that part of the limb, which was but even now nick’d or indented in, is now protuberant, and will presently be sinking again; neither is this all but the whole body of the Luminaries, do in the _Telescope_, seem to be depress’d and flatted, the upper, and more especially the under side appearing neerer to the middle then really they are, and the right and left appearing more remote: whence the whole _Area_ seems to be terminated by a kind of Oval. It is further observ’d, that the body, for the most part, appears red, or of some colour approaching neer unto it, as some kind of yellow; and this I have always mark’d, that the more the limb is flatted or ovalled, the more red does the body appear, though not always the contrary. It is further observable, that both fix’d Stars and Planets, the neerer they appear to the Horizon, the more red and dull they look, and the more they are observ’d to twinkle; in so much, that I have seen the Dog-starr to vibrate so strong and bright a radiation of light, as almost to dazle my eyes, and presently, almost to disappear. It is also observable, that those bright scintillations neer the Horizon, are not by much so quick and sudden in their consecutions of one another, as the nimbler twinklings of Stars neerer the Zenith. This is also notable, that the Starrs neer the Horizon, are twinkled with several colours; so as sometimes to appear red, sometimes more yellow, and sometimes blue, and this when the Starr is a pretty way elevated above the Horizon. I have further, very often seen some of the small Starrs of the fifth or sixth magnitude, at certain times to disappear for a small moment of time, and again appear more conspicuous, and with a greater luster. I have several times, with my naked eye, seen many smaller Starrs, such as may be call’d of the seventh or eighth magnitude to appear for a short space, and then vanish, which, by directing a small _Telescope_ towards that part they appear’d and disappear’d in; I could presently find to be indeed small Starrs so situate, as I had seen them with my naked eye, and to appear twinkling like the ordinary visible Stars; nay, in examining