Note 8 — Chapter I · Earliest Stages of Astronomy.
Reading edition
Ideler (Chronol. i. 242) says that this rising of the Pleiades took place at a time of the year which corresponds to our 11th May, and the setting to the 20th October; but this does not agree with the forty days of their being “concealed,” which, from the context, must mean, I conceive, the interval between their setting and rising. Pliny, however, says, “Vergiliarum exortu æstas incipit, occasu hiems; semestri spatio intra se messes vindemiasque et omnium maturitatem complexæ.” (H. N. xviii. 69.) The autumn of the Greeks, ὀπώρα, was earlier than our autumn, for Homer calls Sirius ἀστὴρ ὀπωρινός, which rose at the end of July.