Page:Popular Science Monthly Volume 45.djvu/852

830 by a throne of massive gold, in which the sun was to come and sit on that day, illuminating the tower on all sides.

The amantas perceived that only four moons passed when the shadow was turned toward the north, while there were eight moons when it was directed toward the south. They did not take into account that their observatories were situated between the equator and the tropic of Capricorn. But when the Incas had established their residence at Quito, their men of science immediately remarked that the two shadows were equal, and that the duration of their variations was exactly six moons. This is why the columns called equinoctial at Quito were especially venerated as the favorite abode of the great divinity.

Mr. Wiener mentions another astronomical apparatus which was intended for the precise verification of the time of the equinoxes: "A vertical well, dug mathematically in the line of the zenith, twice a year, in spring and autumn admitted the rays of the sun and gave light in its lowest depth to a vast tunnel over which it was bored. These observatories were called intihuatanas. These intihuatanas were doubtless real, but the assignment of such a purpose to them was a work of pure imagination." This apparatus, ingenious as it may have been, is too sensibly removed from historical tradition and from the study of the ruins of the solar temples to have really existed. It should further be remarked that such an observatory could be mathematically of service only for the September equinox.

In tracing the meridian the Incas appear to have limited themselves to raising a pillar perpendicular to the line which the shadow follows on the day when the sun passes the zenith, and that they reached this result by a series of trials. This accounts for the variations of a few minutes offered in the orientation of some of the monuments.

The Inca method of determining the solstices was very striking, and nothing like it is found with any other people. On this interesting point we can not do better than literally translate Garcilaso, a descendant of the Incas by his mother, who was better informed upon it than any other writer: "The common people counted the years by the crops, and all were acquainted with the summer and winter solstices. They have left conspicuously visible marks of them. There are eight towers which they constructed at the east, and eight others which they constructed at the west of the city afof [sic] Cuzco, arranged in fours, of which two, smaller than the others and about three stories high, were placed between two others much larger. The other two towers were much higher than those which in Spain serve as lighthouses in the seaports and as observatories on the frontiers. These were intended for the astrologers, to give them a good view. The spaces