Among Mountains far removed from the Eye, that will appear of the most beautiful Azure, which is in itself the most obscure; and that will be the most Obscure, which, is the highest, and most covered with Wood; because of the Shrubs found beneath the larger Trees, which being shadow'd from the Sun, appear Dark and Gloomy; Now the illumined Air, interposed between these Shadowy Mountains and the Eye, must of necessity have its Azure heighten'd and made more perfect by means thereof; and the tops of High Mountains, being likewise the more Obscure, by reason of the thinness of their Medium, will have the same Effect on the Air, through which they are viewed. It follows, therefore, from what we have already laid down, that the Mountains themselves, must appear under the same diversity of Azures, with those of the Airs through which they are viewed; and that the tallest, and the shadyest will excel the rest, in the Beauty of their Colour.