The myth of Hercules recovering his cows from Cacus is the same story told in another form:
A strange monster, Cacus, (the comet,) stole the cows of Hercules, (the clouds,) and dragged them backward by their tails into a cave, and vomited smoke and flame when Hercules attacked him. But Hercules killed Cacus with his unerring arrows, and released the cows.
This signifies that the comet, breathing fire and smoke, so rarefied the air that the clouds disappeared and there followed an age of awful heat. Hercules smites the monster with his lightnings, and electrical phenomena on a vast scale accompany the recondensation of the moisture and the return of the clouds.
"Cacus is the same as Vritra in Sanskrit, Azbidihaka in Zend, Python in Greek, and the worm Fafnir in Norse."[1]
The cows everywhere are the clouds; they are white and soft; they move in herds across the fields of heaven; they give down their milk in grateful rains and showers to refresh the thirsty earth.
We find the same event narrated in the folk-lore of the modern European nations.
Says the Russian fairy-tale:
"Once there was an old couple who had three sons."
Here we are reminded of Shem, Ham, and Japheth; of Zeus, Pluto, and Neptune; of Brahma, Vishnu, and Siva; of the three-pronged trident of Poseidon; of the three roots of the tree Ygdrasil.
"Two of them," continues the legend, "had their wits about them, but the third, Ivan, was a simpleton.