PART 1Collecting of weather-signs must have been a practice of considerable antiquity, for man has always drawn his sustenance from the land or from beasts that convert vegetable into animal protein. A hunter must know the best times for hunting; and for the agriculturist it is essential not only to know when the average seasonal changes of weather occur but to have some means of forecasting variations from the normal. We know two Greek collections of weather-signs, and there may have been a third which was older than either of these. Eudoxus of Cnidus, a pupil of Plato and a distinguished mathematician who lived about 390–337 b.c., had written a prose work on astronomy, entitled Phaenomena. This, at the request of Antigonus of Macedon, was put into verse, under the same title, by Aratus of Soli somewhere between 276 and 274 b.c. The Phaenomena of Aratus is a dull, pretentious piece of versification, of interest to us only because it contains a number of seasonal signs which Virgil has scattered about the Georgics. But the astronomical piece is followed by a passage of 422 lines, which has been given the independent title of Diosemiai or Diosemeiai, on the signs of less normal weather. This is undoubtedly the principal source of Virgil's main collection; and from it, therefore, I shall chiefly be quoting. But there does exist another work, Concerning the Signs of Rain, Wind, Storm, and Fair Weather, a prose work in the form of some twenty pages of notes.
Livestock production to feed the planet. Animal Protein: A Forecast of Global Demand Over the Next Years
