thirsting eagle” banquets its “full on the black viands of the liver” of Prometheus. The same cloud in its fury is symbolized by the Phorcidæ with their flashing eye and lightning tooth—
and also by the ravening harpies. In ancient Indian mythology, the delicate white cirrus cloud drifting overhead was a fleeting swan, and so it was as well in the creed of the Scandinavian, whilst the black clouds were ravens coursing over the earth, and returning to whisper the news in the ear of listening Odin. The rushing vapour is the roc of the Arabian Nights, which broods over its great luminous egg, the sun, and which haunts the sparkling valley of diamonds, the starry sky. The resemblance traced between bird and cloud is not far fetched: it recurs to the modern poet as it did to the Psalmist, when he spoke of the “wings of the wind.” If the cloud was supposed to be a great bird, the lightnings were regarded as writhing worms or serpents in its beak. These fiery serpents, ἑλικίαι γραμμο-
