Smithsonian Report, ! 91 2 — Hu-tington 



Plate 7. 



1. Rectangular Fields for Dry Farming on the Gravelly Slope at the Base 

 OF the Great Trinchera of the Magdalena Branch of the Attar River in 

 Northern Sonora, where Dry Farming is now Impossible. 



2. Ruins in Chaco Canyon, New Mexico, at Pueblo Bonita. 



