The further any Object is removed, the less we know of it, and the more imperfectly do we distinguish what it is. The reason is, that the smallest Particles of Objects disappearing the soonest, and the larger becoming invisible, at a yet greater distance; the Object being removed further and further, its parts are more and more dissipated, till at length all the parts, together with their whole, vanish and disappear: The Colour it self being lost and effaced, by means of the Air interposed between the Eye, and the Object.