Some mythologists have compared the hammer of Hephaestus with that of Thor, and have explained it as the emblem of a thunder-god; but it is Zeus, not Hephaestus, who causes the thunder, and the emblems of the latter god are merely the signs of his occupation as a smith.
Indra, the rain-god, slew with a thunderbolt AM or Vitra, who kept back the waters (Oldham, 32 sqq.); the thunder-god of the Iroquois killed the subterranean serpent which fed on human flesh (Hartland iii.
He is represented as specially lord of the elements, the thunder-god.
But the thunder was his most striking manifestation, and no doubt he was primevally a thunder-God, KEpauvcos, Kepauvo(36Xos, Aorpa7raios.
Also the close special association of the European Thunder-God and the oak-tree has recently been exposed.'