"She dwelleth and abideth on the rock, upon the crag of the rock and the strong place" (ver. 28). It is to this that Obadiah refers when he takes up his parable against the Edomites. They too were rock-dwellers, who had made for themselves houses and founded cities in the rocky fastnesses of Mount Seir. But they are reminded that the impregnable and inaccessible heights to which they have resorted will be no defence against Jehovah: "Though thou exalt thyself as the eagle, and though thou set thy nest among the stars, thence will I bring thee down, saith the Lord." It is even added that Edom would become utterly desolate: "As thou hast done, it shall be done unto thee, ... and there shall not be any remaining of the house of Esau." And if the testimony of modern travellers may be accepted, the desolation is mournful enough. In 1848 Miss Harriet Martineau visited Petra, the chief of these rock-cities, and describes it as follows: "Nowhere else is there desolation like that of Petra, where these rock doorways stand wide—still fit for the habitation of a multitude, but all empty and silent except for the multiplied echo of the cry of the eagle, or the bleat of the kid. No; these excavations never were all tombs. In the morning the sons of Esau came out in the first sunshine to worship at their doors, before going forth, proud as their neighbour eagles, to the chase; and at night the yellow fires lighted up from within, tier above tier, the face of the precipice" ("Eastern Life," vol. iii. 5). The Edomite, alas, is gone, though the eagle is still left, and she fixes her habitation on the dizzy crag. II.—THE ACUTENESS OF THE EAGLE’S SIGHT. "From thence she seeketh the prey, and her eyes behold afar off" (ver. 29). The eye of a bird is a marvellous structure. It is a telescope and microscope combined. It has the power of compressing the lens to adapt it to varying distances; and is larger in proportion than the eye of quadrupeds. The kestrel hawk, for instance, feeds on the common field mouse; but this tiny creature is so like the colour of the soil, that a human eye could scarcely detect it at the distance of a few yards. The kestrel, however, has no such difficulty. Her telescopic eye sees it from the sky overhead, and like a bolt from the blue, she swoops down upon the helpless prey. No mistake is made as she nears the ground. Swiftly and almost instantaneously the telescope is compressed into the microscope, and the daring freebooter could pick up a pin.