And secondly, That it is not meerly the colour of the Air interpos’d, will, I suppose, without much more difficulty be yielded, seeing that we may observe a very great _interstitium_ of Air betwixt the Object, and the Eye, makes it appear of a dead blew, far enough differing from a red, or yellow. But thirdly, That it proceeds from the refraction, or inflection, of the rays by the _Atmosphere_, this following Experiment will, I suppose, sufficiently manifest. Take a sphærical Crystalline Viol, such as is describ’d in the fifth Figure ABCD, and, having fill’d it with pure clear Water, expose it to the Sun beams; then taking a piece of very fine _Venice_ Paper, apply it against that side of the Globe that is opposite to the Sun, as against the side BC, and you shall perceive a bright red Ring to appear, caus’d by the refraction of the Rays, AAAA, which is made by the Globe; in which Experiment, if the Glass and Water be very cleer, so that there be no Sands nor bubbles in the Glass, nor dirt in the Water, you shall not perceive any appearance of any other colour. To apply which Experiment, we may imagine the _Atmosphere_ to be a great transparent Globe, which being of a substance more dense then the other, or (which comes to the same) that has its parts more dense towards the middle, the Sun beams that are tangents, or next within the tangents of this Globe, will be refracted or inflected from their direct passage towards the center of the Globe, whence, according to the laws of refractions made in a triangular _Prism_, and the generation of colour set down in the description of Muscovi-glass there must necessarily appear a red colour in the _transitus_ or passage of those tangent Rays. To make this more plain, we will suppose (in the sixth _Figure_) ABCD, to represent the Globe of the _Atmosphere_, EFGH to represent the opacous Globe of the Earth, lying in the midst of it, neer to which, the parts of the Air, sustaining a very great pressure, are thereby very much condens’d, from whence those Rays that are by inflection made tangents to the Globe of the Earth, and those without them, that pass through the more condens’d part of the _Atmosphere_, as suppose between A and E, are by reason of the inequality of the _medium_, inflected towards the center, whereby there must necessarily be generated a red colour, as is more plainly shewn in the former cited place; hence whatsoever opacous bodies (as vapours, or the like) shall chance to be elevated into those parts, will reflect a red towards the eye; and therefore those evenings and mornings appear reddest, that have the most store of vapours and halituous substances exhaled to a convenient distance from the Earth; for thereby the inflection is made the greater, and thereby the colour also the more intense; and several of those exhalations being opacous, reflect several of those Rays, which, through an _Homogeneous_ transparent _medium_ would pass