ROBBiN^s^°^] CLIMATE AND EVIDENCE OF CLIMATIC CHANGES 53 



logs, then another thick layer of bark, and so on down for several feet. Below the 

 last layer they found a little spring of clear, running water, which has resumed run- 

 ning since they dug it out after centuries of enforced idleness. So thorough had the 

 ancient owners been in their work that they had even obliterated the long, shallow 

 gallery through which the waters of the spring used to escape [pp. 307-08]. 



The force of these warnings is evident and yet not entirely satisfy- 

 ing when the}'^ are applied to the Rito de los Frijoles and the surround- 

 ing territory. The ancient ruins in the canyon itself once must have 

 housed some hundreds of people even if all the ruins were not inhab- 

 ited contemporaneously, and there is nothing to indicate that they 

 were not practically all occupied at the same time. Bandelier, who 

 is conservative, places the population at 1,500 (op. cit., p. 141). In 

 addition, the ruins of old dwellings are to be found everywhere on 

 the adjacent mesas and scattered throughout the other canyons 

 which cut the plateau. The mesa dwellings are not so situated as to 

 indicate that they were placed on elevated ground- for protection 

 from enemies, and it seems wholly improbable that their occupants 

 would have lived in such places if they were dependent for food on 

 crops in the canyons. It is also inconceivable that they would have 

 lived on the mesas with their water supply in the bottoms of the can- 

 yons, 450 to 600 feet below them, unless the canyons were already 

 occupied and their tillable land was taken up by others. No exten- 

 sive irrigation works on the mesas have yet been discovered which 

 would provide irrigation for crops, and carrying water for irrigation 

 to the mesas from the nearest present sources would have been quite 

 impracticable, yet there is no reason to believe that corn could now 

 grow on the mesas in the vicinity of these ruins. The country is not 

 and proba-bh" has not been rich in game. It is difficult to believe 

 that so many people would have built on the mesas unless they could 

 have raised crops there without irrigation. With fertile , valleys, 

 good water, and better opportunities in the bottoms of the canyons 

 for protection and seclusion from enemies, it seems very much more 

 likely that they would have occupied the valleys alone unless there 

 were more inhabitants than the limited valley areas would support. 

 Hence a logical conclusion is that probably most of the dwellings in 

 the canyons and on the mesas were occupied simultaneously at some 

 period. The fact that it was not necessary to live near the fields 

 would hardly account for the placing of the homes on the high diy 

 mesas, because locating them here would add to the distance and 

 altitude to which the grain and water must be carried. It is also 

 wholly improbable that any great number of springs was destroyed by 

 earthquakes or concealed by the inhabitants on abandonhig the dwell- 

 ings, without many of them, or, indeed, most of them, revealing 

 themselves now by seepage, while if destroyed by desiccation, that 

 would put an end to them and stop seepage. 



