510 AMERICAN ANTIQUITY [Vol. 41, No. 4, 1976] Guernsey, Samuel James expedition. Bureau of American Ethnology 9th 1931 Explorations in northeastern Arizona. Pea? Annual Report, 1887-88, pp. 3-441. body Museum of American Archaeology and Neuman, Robert Ethnology, Harvard University, Papers 12(1). 1967 Atlatl weights from certain sites on the Hill, Malcolm W. northern and central Great Plains. American 1948 The atlatl or throwing stick: a recent study Antiquity 32:36-53. of atlatls in use with darts of various sizes. Parker, Arthur C. Tennessee Archaeologist 4:37-44. 1917 Notes on the banner stone with some Kidder, A. V., and S. J. Guernsey inquiries as to its purpose. New York State 1919 Archaeological explorations in northeastern Museum Bulletin 196:165-76. Arizona. Bureau of American Ethnology, Peets, Orville H. Bulletin 65. 1960 Experiments in the use of atlatl weights. 1921 Basket-Maker caves in northeastern Arizona. American Antiquity 26:108-10. Peabody Museum of American Archaeology Spencer, B., and F. J. Gillen and Ethnology, Harvard University, Papers 1899 The native tribes of central Australia. 8(2). London. Mallam,R. Clark Sweatman, John from 1971 An atlatl weight southeast Nebraska. 1848 Journal of a surveying voyage to the north? Plains Anthropologist 16:123-24. east coast of A ustralia and Torres' Sts, in Her Mason, J. Alden Maj. Schooner, Bramble, Lieut. C. B. Yule, of 1928 Some unusual spear throwers ancient Commander, 184247. Mitchell Library, MS. Museum Journal 19:290-324. America. The Al725. Cambridge. University of Pennsylvania. Webb, William S. Clayton Mau, 1946 Indian Knoll. University of Kentucky, 1963 Experiments with the spear thrower. The in 4(3, 1). New York State Archaeological Association Reports Anthropology pt Bulletin 29:1-13. Webb, William S., and David L. De Jarnette 1942 An of Pickwick Basin McGregor, John C. archaeological survey of the states of 1965 Southwestern archaeology. University of in the adjacent portions Bureau Illinois Press, Urbana. Alabama, Mississippi, and Tennessee. of Bulletin 129. Metcalf, George, and Harold Carlson American Ethnology, 1971 An atlatl weight from North Dakota. Plains Webb, William S., and William G. Haag Anthropologist 16:121-22. 1939 The Chiggerville shell heap in Ohio County. Murdoch, John Department of Anthropology and Archaeology, 1892 Ethnological results of the Point Barrow University of Kentucky, Publication 4(1). ON THE ORIENTATION OF PRECOLUMBIAN BUILDINGS IN CENTRAL MEXICO Anthony F. Aveni Sharon L. Gibbs A tendency for many precolumbian buildings toyalign east of north is examined for possible astronomical motives. Stellar and solar phenomena are suggested as possible influences. The importance of clearly establishing the relative positions of observer and point of reference in any archaeo-astronomical analysis is emphasized. Certain misconceptions concerning chronological correlations of alignments and a new dimension in establishing orientations are discussed. One fact which emerges from a careful study sites, and that architects copied the sacred of the orientation of many precolumbian build? direction by laying out an astronomical baseline ings of Central Mexico is the tendency for their at the model site and transferring it to the new north-south axes to align slightly east of ceremonial centers. This same orientation ap? astronomical north. In an earlier paper, Aveni pears in the Toltec period buildings at Chichen (1975) reported that, on the basis of measure? Itza (Aveni, Gibbs, and Hartung 1975). The ments made with a surveyor's transit, three present paper reports the results of measure? Central Mexican sites (Tepozteco, Tenayuca, ments taken with a transit during January 1974 and Tula) possess nearly the same orientation as at ten additional sites in Central Mexico and Teotihuacan (15? 25' E of N). It is likely that suggests possible astronomical motives for the Teotihuacan served as a model for the other orientations thus found. REPORTS 511 The orientations of all Central Mexican sites We find no correlation between site axiality studied to date are listed in Table 1. The and site latitude or time of construction. The measuring techniques employed and range of axis of Cuicuilco, the earliest building of those accuracy have been discussed elsewhere (Aveni we measured, shows a clockwise skew ranging 1975). Building periods range from approxi? from 1?43' to 7?38', depending upon which mately 500 B.C. to A.D. 1500, but because of measurement can be accepted given the ruined the uncertainty of the dates of completion of state of the stairway leading to the top of the many structures, exact times are excluded from building. On the other hand, the Teopanzolco the table. Fig. 1 is a polar diagram showing the pyramid in Cuernavaca, one of the latest averaged orientation of each measured site. In precolumbian buildings to be constructed, has all 14 cases the axes are skewed clockwise from its outer face skewed clockwise from the the cardinal directions, ranging from 0?25' E of cardinal points by only 00?43'. At Tlatelolco, N at Xochicalco to 27?05' E of N for the the largest structure exhibits nine different Teotihuacan period ball court at Manzanilla, building phases. The orientations range between Puebla. In no case is an axis displaced counter- 7?39' and 11?47' E of N, but again no clockwise from the cardinal directions. systematic time variation is found to occur. N ? E Fig. 1. Axial orientations of Central Mexican ceremonial centers. The orientations shown in Table 1 are averaged for a given site. Both Xochicalco orientations are shown. 512 AMERICAN ANTIQUITY [Vol. 41, No. 4, 1976] Table 1. Orientation of buildings determined with surveyor's transit. Site Structure Alignment Orientation Remarks Teotihuacan Street of Dead Axis 15? 25' E of N Ref. Million (1974) Lat. 19?42'N Long. 98?51'W E-W Street Axis 16?30'SofE Ref. Million (1974) Ciudadela Principal axis 16?55'SofE Ref. Million (1974) Tenayuca Pyramid Base of steps on West 17 42 WofS Building faces West. Lat. 19?31'N wall looking South Postclassic Long. 99?11'W South wall looking West 16? 27' N of W Tepozteco Temple Base of steps on West 18?00' W of S Building faces West. Lat. 19?00'N wall looking South Postclassic Long. 99?06'W Tula Temple B Base of steps on South 17? 10' N of W Building faces South Lat. 20?05'N wall looking West Long. 99?24'W North Ballcourt West wall looking North 16? 25' EofN Axis of ballcourt is 17?06' EofN E-W South wall looking East 14?55' SofE 14?13'SofE East Ballcourt West wall looking North 15?04' EofN Axis of ballcourt is N-S Tula Chica Base of steps looking 09? 02' EofN Building faces East. Circular Temple North Postclassic Tenoch titlan Templo Major South wall looking 07? 06'SofE Building faces West. Lat. 19?27'N East Postclassic Long. 99? 08'W Tlatelolco Principal structure West walls looking North 11?47' EofN 9 consecutive Lat. 19?28'N 09?57' EofN building phases, Long. 99? 08'W 09?43' EofN listed in chronolog- 09?36' EofN gical order top to 08?58' EofN bottom. Building 09?30' EofN faces West. 09?09' EofN Postclassic 09?30' EofN 07?39' EofN Teotenango Base of acropolis West stairway looking 13?33' EofN Single measurement Lat. 19?08'N North on western base. Long. 99?35'W Postclassic Teopanzolco Principal structure Base of steps on West 00?43' EofN Building faces West. Lat. 18?49'N wall looking North Postclassic Long 99? 17'W Cuicuilco Circular temple Various portions of 07?38' EofN Building faces East. Lat. 19?18'N base of steps looking 05?42'EofN Preclassic Long. 99?11'W North 01?43' EofN Calixtlahuaca Temple of Tlaloc Base of steps on East 01?50' WofS Building faces East. Lat. 19?20'N wall looking South Postclassic Long. 99?40'W Temple of Base of steps on East 01? 12' WofS Building faces East. Quetzalcoatl wall looking South Postclassic (Circular temple) Chalcatzingo Steps leading to Base of steps (lower) 17? 17'SofE Building faces North. Lat. 18?42'N principal reliefs looking East Preclassic Long. 98?46'W Base of steps (upper) 21?22'Sof E looking East REPORTS 513 Table 1. (Continued) Site Structure Alignment Orientation Remarks Cholula Base of Adosada South face looking 26? 16' S of E Building faces West. Lat. 19?03'N East Classic Long. 98? 18'W Manzanilla Teotihuacan period Axis 27?05' N of W Axis of ballcourt is Lat. 19?08'N ballcourt E-W. Classic Long. 98?08'W Aztec period South wall looking 27? 02' N of W Axis of ballcourt is ballcourt West E-W. Postclassic Xochicalco Structure E South wall looking 00? 25' N of W Building faces South Lat. 18?47'N West Long. 99?17'W Ballcourt South wall looking 00?44' N of W Axis of ballcourt is West E-W Temple of Plumed Base of steps on West 16?45' W of S Building faces West. Serpent wall looking South 17? 13' WofS Classic At some sites a conscious effort to preserve a "the priest and worshippers doubtless faced to the to watch the in the particular alignment in spite of intervening east, sun rise space between the two oratories." [See Fig. 2]. terrain is indicated. Two temples at Calixtla- huaca are good examples. They align nearly Maudslay's inference is further supported by a in the same direction even precisely though 1524 map of the Aztec capital which shows a are 100 meters and at different they apart face representing the sun flanked by the twin the measured axes are directed 1?50' elevations; temples (Huicholobos) on the top of the SofE and 1?12' S of E.