21.

Some writers tell us there are but two principal winds, the north and south, and that the other winds are only a slight difference in the direction of these two. That is, (supposing only two winds, the north and south,) the south wind from the commencement of the summer quarter blows in a south-easterly direction; and from the commencement of the winter quarter from the east. The north wind from the decline of the summer, blows in a westerly direction, and from the decline of the winter, in a north-westerly direction.

In support of this opinion of the two winds they adduce Thrasyalces and our poet himself, forasmuch as he mentions the north-west with the south,

But Posidonius remarks that none of those who are really acquainted with these subjects, such as Aristotle, Timosthenes, and Bion the astronomer, entertain so mistaken an opinion in regard to the winds. They say that the north-east (Cæcias) blows from the commencement of summer, and that the south-west wind (Libs), which is exactly opposite to this, blows from the decline of winter. And again, the south-east wind (Eurus), which is opposite to the north-west wind (Argestes), from the commencement of winter. The east and west winds being intermediate.

When our poet makes use of the expression “stormy zephyr,” he means the wind which is now called by us the north-west; and by the “clear-blowing zephyr” our west wind; our Leuconotus is his Argestes-notus, or clearing south wind,171 for this wind brings but few clouds, all the other southern winds bringing clouds and rain,172

Here he alludes to the stormy zephyr, which very frequently scatters the feathery clouds brought up by the Leuconotus, or, as it is called by way of epithet, the clearing south.

The statements made by Eratosthenes in the first book of his Geography, require some such correction as this.