1911 Encyclopædia Britannica, Volume 13… (1911)
“ It is doubtful whether the origin of the god can be traced to any specific form of fire. As all earthly fire was thought to have come from heaven, Hephaestus has been identified with the lightning. This is supported by the myth of his fall from heaven, and by the fact that, according to the Homeric tradition, his father was Zeus, the heaven-god. On the other hand, the lightning is not associated with him in literature or cult, and his connexion with volcanic fires is so close as to suggest that he was originally a volcano-god. ”
