[120] This plate has been drawn from the globe adjusted to the dates and latitudes of 5744 B.C. Lat. 18° N., and of 3588 B.C., Lat. 23° N.
In Grecian legend Cepheus, Cassiopeia, Andromeda, the sea-monster (Cetus), and Perseus are associated together, and on the Grecian sphere five neighbouring constellations represent the actors of the legend.
Studying these constellations as they must have appeared to observers of the heavens at different dates, we shall, I think, see some reason to attribute the imagining of the figure of the hero Perseus to a later age than that of the other members of the group, and, on the other hand, there are considerations which may make us hesitate whether we should not place the origin of the constellation Andromeda at an even earlier date than those of Cepheus, Cassiopeia, and the sea-monster.[121] One point in the legend, however, finds strong astronomic support from a study of the precessional globe—namely, the fact that Cepheus and Cassiopeia were personages of Ethiopian—i.e., of tropical provenance.
[121] See below at [p. 246], and [pp. 242], [243].
It will be seen in [Plate XXII., fig. 1], that only in a latitude as far South as 18° N. could the figure of Cassiopeia—even at the early date of 6000 B.C.—have been imagined as that of a queen seated in royal dignity, and visible in the northern quarter of the heavens.
By referring to [Plate XV.], we may learn that in Lat. 45° N. at that date, Cassiopeia would have appeared in the southern quarter of the sphere, head downwards, while the figure of Cepheus could only have been observed by turning first to one and then to the other quarter of the sky. As, however, the head of Cepheus would have marked so exactly the solstitial colure 6000 B.C., it seemed to me only right to seek for a latitude in which his figure and that of his queen should appear upright and in the same quarter of the heavens—a latitude, therefore, in which it might be possible to suppose these constellations had been originated as star-marks of the solstitial season. To attain this object it was necessary to set the globe to the very low latitude of 18° N.
To suppose at 6000 B.C. so wide a diffusion, not only of the human race, but also of astronomical science and authority, seemed to involve an historical unlikelihood. Moreover, even if for the sake of suitably establishing the dignity of this regal pair one were tempted to suppose the great improbability of schools of astronomy existing, and with equal authority instituting constellations as star-marks for the year, in regions as far north as Lat. 45° N. and as far south as 18° N.—even so, I do not think the position of the constellations themselves in relation to the solstitial colure as shown in the diagram is by any means so convincingly symmetrical as to force us to accept the date 6000 B.C. for their origin. The head only of Cepheus appears on the meridian, his figure and the whole constellation of Cassiopeia lie considerably to the east of that line.
Under these circumstances it is satisfactory to find at a later, and therefore at a more historically probable date, and still in an Ethiopian (tropical) latitude, a meridian line on and about which the constellations Cepheus, Cassiopeia, Andromeda, and Cetus form a well-balanced group.
This meridian, it is true, is not that of a solstice or an equinox; but it is one which marked a very important astronomical moment—namely, the commencement of the calendrical year—the year counted from the entry of the sun into the constellation Aries. (See [Plate XXII., fig. 2].)
Of the high calendrical importance attached through thousands of years to this point in the sun’s annual course by the Accadian and Babylonian nations and by the Hindus down to the present day, astronomic records testify. Egyptian mythology and Chinese traditions also, as I have claimed, refer to it: it need not, therefore, surprise us to find constellations imagined to mark the beginning of a year counted from that point, even at a date when this beginning did not coincide either with solstice or equinox.