MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 147 



Communal houses. The great structures thus designated were the principal dwelling places. 

 They were built of mud without the central frame of hurdles on which the walls of the temples 

 were raised. They contained many rooms on the ground floor, and, as there is evidence that they 

 were sometimes more than one story high, it is not improbable that they resembled much the 

 modern terraced pueblos of New Mexico and Arizona. They were too large for the dwellings of 

 single families, and for this and other reasons they are thought to have been each the home of a 

 separate gens, clan, or some other large subtribal division. Each was surrounded by a separate 

 high earthen wall and generally by a separate canal or acequia, although, in a few instances, two 

 or more communal dwellings were included in the same encircling canal. Each had its single 

 appropriate water reservoir with a branch canal leading into it, its one separate pyral mound or 

 place of cremation, and its one great underground oven for the preparation of food. In Los 

 Muertos at least fifty of these great buildings were wholly or partially unearthed, and it is likely 

 that many more remained unrevealed beneath the surface of the ground. 



Ultra-mund houses. These were small, low huts, not rectangular in form, made of sticks, 

 reeds, and similar perishable material, lightly coated with mud, and they probably resembled 

 much the modern jnkal or hut of the lower classes in many parts of Mexico, or the houses of the 

 present Pima Indians of the Gila Valley. Mr. Cushiug calls them ultra-mural or ultra-urban 

 because they were situated outside the limits of the towns of earthen houses and not mingled 

 with them; they formed separate groups. He conjectures that they may have been residences of 

 an outcast population such as exists at Zufii to-day. As each contained a central fireplace it is 

 evident that they were occupied in winter as well as in summer, and were, therefore, not like 

 certain houses scattered through the fields of the modern Zufiis, used only as temporary shelter 

 for laborers while the crops are growing. These ultra-mural dwellings were very numerous; in 

 one place constituting, of themselves, a town of considerable size, which contained a sun temple 

 but no priest temple. In estimating the age and character of some, at least, of these houses, it 

 must not be forgotten that as late as the seventeenth and eighteenth centuries we have records 

 of the existence of Pima villages in the lower part of the Salt lliver Valley. I make this state 

 ment on the authority of Mr. Bandolier. 



AGRICULTURE AND WATER SUPPLY. 



When these ruins were inhabited cities, the land in which they lie was, as it now is, an arid 

 region, where agriculture could not be conducted without irrigation. The works constructed by 

 the ancient inhabitants to establish irrigation are as noteworthy monuments to their industry and 

 intelligence as are their stupendous buildings. The explorers have traced in this particular realm 

 in the Salado Valley, they estimate, over 150 miles of the larger canals the mother acequias or 

 cm-quids madres, as the Spanish-Americans call them. Their remains have been found at dist ances 

 of 12 and 15 miles from the present bed of the river, and there is no evidence that the river has 

 materially changed its course since the days of the ancient inhabitants. The miles of smaller 

 acequias could not be estimated. 



The larger canals varied in width from 10 to 30 feet and in depth from 3 to 12 feet. Their 

 banks were terraced in such form as to secure always a uniform central current in the canal when 

 the rains ceased in the mountains and the waters diminished. It is thought that this device was 

 to facilitate navigation, and that the canals were used not only for irrigation, but for the trans 

 portation of the produce of the fields and of the great timbers from the mountains which the people 

 must have needed in the construction of their tall temples and other houses. 



In various parts of our arid region the old Indian canals may be still easily traced where they are 

 cut through hard soil or where they are so exposed and situated, with regard to the prevailing 

 winds, that the sand is blown out of them rather than drifted into them. There are places in 

 Arizona where the American settlers utilize old canal beds for wagon roads. But in most cases 

 the canals have been filled with sand and clay to the level of the surrounding soil and, to the 

 ordinary observer, no vestige of them remains. Yet Mr. Gushing, guided by his knowledge of a 

 custom which exists among the Zuni Indians, was able to trace the course of these obliterated 

 channels. These Indians, he relates, have observed that wherever there is running water there 

 are rounded pebbles and boulders; reasoning, a^ man is so apt to do, inversely to the natural order 



