SMITHSONIAN' INSTITUTION 





Fig. 159. — One of the prehistoric canals preserved by Phcenix, Arizona, in its 

 Park of the Four Waters. 



i?^-^ 



Fig. 160. — An ancient canal, at the upper right, was bisected by Salt River 

 long before the Swilling ditch, in the foreground, was dug about 1868. 



