214 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I47 



were indefatigable builders. They were continually tearing down and 

 replacing perfectly serviceable structures and the waste from such 

 activities, along with their daily household sweepings, was carried 

 out and dumped south of the pueblo. But, as we later learned to 

 our astonishment, these discards had filled a broad, pre-Bonito 

 floodway several feet deep before they began to pile up to form the 

 two principal refuse mounds under consideration. 



The Hyde Exploring Expedition in 1896 trenched both East and 

 West mounds in search for Bonitian burials (Pepper, 1920, p. 26), 

 and others on the same quest had been there before. Pepper does not 

 elaborate upon these operations, but his pre-excavation view from 

 the north cliff (ibid., fig. 3, p. 20) shows both trenches, the larger 

 crossing the West Mound opposite Rooms 138-140 and, on either 

 side of it, lesser trenches exposing the north enclosing wall. 



In July 1916, two years after his important pioneering studies 

 in the Galesteo Basin, New Mexico, N. C. Nelson, of the American 

 Museum of Natural History, sought stratigraphic data from these 

 same Bonito mounds — the first inquiry of its kind undertaken here — 

 and his findings were hastily summarized four years later for inclu- 

 sion in the Pepper volume (ibid., pp. 383-385). Nelson apparently 

 took advantage of the two Hyde Expedition trenches for a vertical 

 cut was to be seen at the side of each in 1920, the year of the 

 National Geographic Society's Chaco Canyon reconnaissance (pi. 3). 



As the one who introduced stratigraphy as a method of archeo- 

 logical analysis in the Southwest and who elsewhere had built a 

 foundation for all subsequent research in this field. Nelson was both 

 surprised and disappointed with the results of his observations in 

 Pueblo Bonito refuse. He was disappointed because his sherd totals 

 disclosed less evidence than he had anticipated, and he was surprised, 

 as I was, by the incredible quantities of refuse from razed buildings. 



Nelson's observations were restricted to two vertical columns, each 

 2 by 4 feet, which he divided arbitrarily into 6-inch layers for the 

 recovery and study of potsherds. From the first column, in the West 

 Mound and 16 feet deep, he recovered 1,083 fragments; from the 

 East Mound column, 11^ feet deep, 1,040 fragments. These he 

 sorted into four principal groups — corrugated, black-on-white, red, 

 and shiny black — and then subdivided each lot on the basis of orna- 

 mentation. There were more than 20 varieties in the black-on-white 

 group alone. 



In the upper layers Nelson expected to find only black-on-white 

 sherds bearing hachured designs, or a combination of hachured and 



