The proofs that the Incas. . . had a real system of astronomy are scattered, partly in what remains of the monuments that were consecrated to the sun, and partly in the accounts of historians—accounts which, whether because their importance has not been suspected, or because of the difficulty of quoting them, most of them having been printed only once, others having remained in the state of manuscript, and very few of them having been translated, are but little known to men of science. Whatever the verity of the legends preserved in these accounts, we find a comparatively highly developed astronomical system among the Incas, of which the most interesting parts are here given from rare documents already published, and from American manuscripts and traditions. The work has not before been done so completely.
Six nations only—China, Mongolia, India, Chaldea, Egypt, and Australia—had, before the discovery of America, divided the visible celestial sphere into constellations, and had used figures of their own invention to represent them. The Peruvians, although situated at the meeting of the Northern and Southern hemispheres, did not extend their division over the whole sphere; they recognized and studied only a few of the more brilliant constellations, like the Pleiades, the Jaguar, the Standard, the Southern Cross, and some other groups which have not yet been identified.[1] It is probable that they extended this division further than the first historians—who were not learned in astronomy, and could therefore pay little attention to all the details—represent. Later writers speak of other constellations which they do not mention. The Incas called the milky way the dust of stars, and gave names to its different parts. What is now called the Coal Sack was figured by them as a doe suckling her fawn—a simple and poetic transformation of the Grecian and Aryan legend of Hercules and his nurse.[2] A few stars of the first magnitude, such as Capella and Vega, had special names.[3] It is almost impossible that the Incas should have failed to give distinct names to the splendid stars of the Southern hemisphere, such as Sirius, Canopus, Achernar, etc. The silence of historians respecting this point is far from being conclusive, and may be accounted for by supposing that many of these stars not being visible in our hemisphere, they did not ask the natives for their names, and limited their inquiries to the stars of the Northern hemisphere which they knew.
The only planet which the Incas had discovered was Venus, which they called the hairy, on account of the brightness of its
