The life led by the ancients was rude and illiterate; still, as will be readily seen, the observations they made were not less remarkable for ingenuity than are the theories of the present day.Pliny the Elder
Kamoun Lab have reminded me via their Scoop It page that today is the day of the Robigalia, a Roman festival to protect the corn crop. Actually reminded is the wrong word. Told is better as I really can’t remember anything about the Robigalia. This is a bit embarrassing as my PhD was partly about astronomy and ancient festivals, and the Robigalia has this in abundance. The best source available online is Pliny’s Natural History chapter sixty-nine, Causes of Sterility, where the above quote comes from. It continues…
With them there were three set periods for gathering in the produce of the earth, and it was in honour of these periods that they instituted the festive days, known as the Robigalia, the Floralia, and the Vinalia.
The Vinalia, a festival for wine production, has already passed us on April 20. Pliny notes: “This, again, is another period of four days, which should never be blemished by dews, as the chilling constellation of Arcturus, which sets on the following day, will be sure to nip the vegetation; still less ought there to be a full moon at this period.”
The links provided by Kamoun Lab are much better than anything I could write about the Robigalia, but there’s something worth noting here too. Why sacrifice a puppy? From the Encyclopaedia Romana:
Columella does speak of a young dog being sacrificed to appease the goddess (De Re Rustica, X.342ff; also Pliny, XVIII.15), and fragments from Festus (XLVIII, CCLXXXV) indicates that red dogs were sacrificed to appease the Dog Star that the corn might ripen. All are examples of homeopathic magic, where the desired event is imitated or mimicked. Here, the withering Dog Star is signified by a sacrificial dog, its color representing red rust (or the ripening corn).
Finally comes the Floralia on April 28. Corn was again an issue, as were blossoming plants. From Pliny again: “If there should happen to be a full moon during the four days at this period, injury to the corn and all the plants that are in blossom, will be the necessary result.”
The interesting feature connecting all three events is not that the movement of stars defines the time to do something, but that the stars directly affect agriculture. For example at the Robigalia, Sirius is low in the evening sky. Soon it will be so low in the evening sky it’ll be below the horizon before it’s dark enough to see it. Because of it being close to the Sun it’s lost in the Sun’s glare for about forty days. The Romans wouldn’t see it again till it rose a few minutes before the Sun at high summer.
The Greeks used these events as part of a rough calendar to mark out the year, but in the passages above it’s clear the Romans aren’t doing this. It isn’t the time of year that’s causing wheat rust. It’s that today the Romans would only see Sirius touch the horizon and it’s the act of the red Dog-Star touching the Earth than can transmit wheat rust. So they’d sacrifice a puppy to propitiate the gods on this day.
It is weird, or at that’s how it looks to me. There is a book due out (since August last year) by Gavin Hardy called Ancient Botany. I’m looking forward to reading it. The way plants were perceived to work obviously affects how you read the ancient evidence if you want to use it in modern studies. Seeing how the Robigalia surprised me, I’m expecting a whole series of “I never realised that!” moments.