Each clock-star, if it rose and set very near the north point, might be depended on to herald the sunrise on one of the critical days of the year, but for the others other stars would require to be observed. This practice was fully employed in Britain.
May Warnings.
—The following table gives the stars I have so far noted which were used as warners for the May festival.
| Monument. | Star. | Date or dates B.C. |
|---|---|---|
| Stonehenge | Pleiades (R) | 1950 |
| Merry Maidens | Pleiades (R) | 1930 |
| Antares (S) | 1310 | |
| The Hurlers | Antares (S) | 1720 |
| Pleiades (R) | 1610 | |
| Merrivale | Pleiades (R) | 1610 |
| „ | 1420 | |
| Boscawen-un | Pleiades (R) | 1480 |
| Tregaseal | Pleiades (R) | 1270 |
| Stenness | Pleiades (R) | 1230 |
| Longstone (Tregaseal) | Pleiades (R) | 1030 |
| (R) = rising. (S) = setting. | ||
It is convenient here to give a list of the May warning stars found by Mr. Penrose in Greece, as it shows that the same stars were observed for the same purpose.
| Decl. | Day. | Year. | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| B.C. | ||||||||||
| Archaic temple of Minerva | Pleiades | (R) | + | 7 | ° | 50 | ′ | April | 20 | 2020 |
| Hiero of Epidaurus, Asclepieion | „ | (R) | + | 9 | 15 | „ | 28 | 1275 | ||
| Hecatompedon | „ | (R) | + | 9 | 58 | „ | 26 | 1150 | ||
| Older Erechtheum | Antares | (S) | - | 14 | 31 | „ | 29 | 1070 | ||
| Temple of Bacchus | Pleiades | (R) | + | 10 | 35 | „ | 29 | 1030 | ||
| Corinth | Antares | (S) | - | 16 | 0 | May | 6 | 770 | ||
| Aegina | „ | (S) | - | 16 | 45 | „ | 7 | 630 | ||
The warning stars at Athens were the Pleiades for temples facing the east, and Antares for temples using the western horizon.
August warnings.
—Sunrise at the August festival was heralded by the rising of Arcturus, which, as we have seen, was also used as a clock-star. The alignments and dates given in the Arcturus table therefore hold good for August. At the Hurlers, where the hill over which Arcturus was observed fell away abruptly, we find Sirius supplanting Arcturus as the warning star for August in 1690 B.C.