Excavation of Aztec Ruins 101 



large part of the western half of the main ruin. Some six- 

 teen rooms were found with their ceilings intact, thus giving 

 us full opportunity to study the architecture in all its de- 

 tails. Though the walls of the ruin are of dressed sand- 

 stone, the ceilings are of wood supported by large beams of 

 cedar and spruce. The presence of these logs has enabled 

 us to introduce a novel method of estimating the age of the 

 ruin. Professor A. E. Douglass, who has developed ingenious 

 methods by which the annual rings of trees can be dated, even 

 though the logs are of unknown age, was invited to examine 

 cuttings from the ruins in this group and from Pueblo Bonito 

 in the famous Chaco Canon group, explored for this Museum 

 by the Hyde Expedition. The investigation is now proceed- 

 ing with satisfactory results, a report of which will be 

 published later. 



For the most part the members of our scientific staff gave 

 their time to the data obtained on former field expeditions. 

 Problems of racial distinction and origins were 

 in the developed by Assistant Curator Sullivan and Dr. 



Museum Bruno Oetteking. Mr. Sullivan, with the co- 



operation of the Department of Physiology, made a series of 

 microphotographs of racial hair cuttings for study and exhi- 

 bition. The main investigation, however, concerned itself 

 with a series of measurements upon full and mixed-blood 

 Indians made some years ago under the direction of Professor 

 Franz Boas. These data have been thoroughly compiled and 

 correlated to show the results of race mixture. Among some 

 of the significant conclusions are the constancy of degrees of 

 correlation between bodily proportions even in mixed-bloods 

 and the apparent inheritance of specific correlations between 

 face width and breadth of head. Dr. Oetteking completed 

 the measurement and description of the skulls for north- 

 western America and eastern Siberia, for a report upon the 

 physical anthropology of the Jesup North Pacific Expedition. 



Our facilities for promoting research in human biology have 

 been greatly improved during the year. A room adjoining 

 the physiological laboratory has been equipped as an an- 



