In the planisphere of the portico, as well as in that of the temple, the figure supposed to be that of Cancer is placed on one side of the position which it should occupy among the zodiacal constellations ; and this circumstance has given rise to concerning the justness of that supposition. Some persons have imagined that the figure might have been intended for the mythological searabeus ; but as in this temple, as well as iu those at Esne, it has eight feet, while the scarabeus has but six, it is more probable that it represents the zodiacal sign ; and that, agreeably to the hypothesis of Biot, the displacement was in ordCr to make room for some emblem. In fact, the place of Cancer is, in the portico, occupied by a head of leis, which is plunged in the solar rays; and, since Sirius was consecrated to leis, it is reasonable to suppose that the emblem was intended to express that, at the epoch of the planispheres, the star Sirius rose heliacally. By calculation it is ascertained that about 700 years before Christ, in the latitude of Denderah, Sirius rose with the star of Cancer when the sun was in that constellation, that is, at the summer solstice.
The two temples at Esne have, in the ceilings of their porticoes, representations of the twelve zodiacal constellations in two lines parallel to the axes of the buildings. In the smaller temple six of the figures appear to be entering on the southern side, and six to be issuing on the northern side : the front of the portico being towards the east, the direction of their movement corresponds, consequently, to that of the diurnal rotation, as in the temple at Denderah ; but there is this differ ence in the division of the figures, that at Esne, Leo is the last to enter, and Virgo the first to quit the temple. M. Blot endeavours to account for this difference by the different inclinations which the axes of the two temples have to the meridian ; the axis of the temple at Denderah deviating 17 degrees, and that of the small temple at Esne 71 degrees, both of them being from the north towards the east. He observes that, in the former temple, a meridian line passing through the centre of the circular plauisphere cuts the zodiacal band in Cancer towards the north, and in Capricorn towards the south ; thus dividing the twelve figures so that the six which are on the western side con stitute all those which at a certain hour are descending towards the west, and those which are on the eastern side are ascending towards the meridian. At the head of this descending series is Leo, which is the first to pass the inferior meridian and enter the eastern series; and at the head of the ascending series is Aquarius, which is passing the upper meridian : this distribution corresponds to that which is repre sented in the zodiac of the portico. A like correspondence would be found to exist in both the temples at Esne if a circular planisphere were supposed to be placed in the ceiling of each, with the lotus-stem in the longitudinal axis, towards the north, and the planisphere were cut by a meridian-line so as to divide the figures into such as ascend and such as descend.
That there were among the ancient Egyptians a variety of sculptured representations of the heavens is evident, since the planisphere described by Scaliger, in his ` Notes on Manilius,' contained, among many animals having no correspondence in form or situation with those which have been mentioned, the figure of a man holding a scythe, and of another who is killing a bear ; and in the ` Momoires de l'Acaddmie des Sciences,' 1708, there is described, by M. Bianchini, a fragment of an Egyptian planisphere consisting of a circular space sur rounded by five concentric bands : in the centre are two bears sepa rated by a serpent, as in the present spheres ; and in the nearest band are twelve figures representing constellations, most of which differ from the zodiacal signs above described ; the place of Gemini, for example, being occupied by a serpent. In the two next bands are the signs of the Greek zodiac, and on the exterior of these is a band divided into 30 parts, in each of which is a deity ; these are the spaces of 10 degrees, into which, in the East, the zodiac was some times divided.
There can be little doubt that the Egyptians and Chaldmeans distin guished the groups of stars in the visible heavens by the figures or symbols of the deities which they worshipped, and of the men who, among them, had signalised themselves by great actions; but it has been also assumed, that the names of the zodiacal constellations were given from circumstances relating to the apparent motion of the sun, to the labours of husbandry, or to the productions of nature in differ ent seasons. Macrobius mentions (' Saturnal. ' lib. 1.) that the constel lation in which the sun is, at the season when he ascends from the winter solstice towards the equator, received the name of Capricronus, because the goat is an animal accustomed to ascend to the highest points of ground ; and that the constellation in which the sun is when he returns from the summer solstice towards the south was designated Cancer from the crab being an animal which is said to have a backward movement. Bishop Warburton in this country, and M. Pluche in France, carrying out the same idea, have imagined that the constella tions Aries, Taurus, and Gemini received their names from the young of animals being brought to the fields in the spring ; that Leo indi cates the violent heats of summer, and Virgo, presumed to be a gleaner, denotes the time of harvest, and so on. M. Dupuis, assuming that the zodiacal constellations were first imagined in Egypt, and that they indicated circumstances connected with the labours of husbandry in the different months of the year, endeavoured to ascertain at what epoch, in the climate of Egypt, the symbols would be in accordance with the circumstances which they were supposed to represent; and the result of his inquiry was, that the agreement could have subsisted only when the vernal equinox was in the constellation Libra. At present it is in the constellation Pisces ; and computing the time during which, by the effect of precession, the equinoctial points would move over about half the circumference of the ecliptic, he assigned 15,000 years before the Christian era for the time of the invention of the zodiac. This extravagant epoch he afterwards reduced to about 4000 years before Christ. (` Origine des Cultes,' 1796.) M. Fourier, in his Recherches sur les Sciences et he Gouvernement de l'Egypte,' assumes that the representation of the head of Isis partly plunged in the solar rays near the figure of Cancer, among the sculp tures in the portico of the temple at Denderah, is an emblem of the hcliacal rising of Sirius when the sun was in the sign, or in the con stellation Cancer ; and observing that Cancer is the last of the figures which appear to enter the portico of that temple, while in the zodiacs at Esne the lion is the last which enters, he conceives that the latter circumstance is an indication of the sun being in Leo when Sirius rose heliacally. Supposing, then, that the epochs of the zodiacs at Denderah and Esne are such as the positions of the sun denote, be determines, by computation founded on progressive displacement of the point of the heliacal rising. that the interval between them is 1800 years, the sculptures at Esne referring to the more ancient period. This result must, however, be considered as overthrown by the calculations of MM. Ideler and Biot, who have determined the longitudes of the sun at the terminations of three sothiac or canicular periods of 1460 years, within which the heliacal risings of Sirius return to the time of the summer solstice; and have found that between the year 2782 B.C. and 139 a.o. the sun was in the constellation Leo and in the sign Cancer at all the three epochs. M. Biot concludes therefore that the zodiacs at Den derah and Esne do not indicate that the sun had passed from one con stellation to the next in the interval between the epochs to which they are supposed to refer.