Scientific Lectures. 289 



scattered over its plains, or crown its castellated crags, but now, almost 

 without exception, abandoned and in ruins. 



At tlie present time the Colorado plateau is, for the most part, a 

 hopeless desert ; but it was at one time as fertile and beautiful as anj 

 portion of our country. 



On the north-eastern side of the plateau the Rocky mountains, 

 where broadest and highest, rise from it as a base. These, acting as 

 a great condenser, cause a copious precipitation of moisture, and 

 supply the water which forms many great rivers, as the Arkansas,, 

 Red river, the Rio Grande and Colorado. 



To resume the thread of my narrative where it was broken for 

 this digression. AVhen we had ascended the western margin of the 

 high plateau, as our special business was to trace the line of the 

 Colorado in the Great canon, we struck north-easterly to reach it 

 again. When still many miles distant from the canon, we found th& 

 plain so cut up by ravines opening northward, that we were comjjelled 

 to descend to the bottom of one of tliem, and take that as our road. 

 "Where we descended, the cliffs were about 500 feet high, and at the 

 bottom was a spring, and — what caused us no little surprise — a peach 

 orchard. Tiiis was in north-western Arizona, several hundred miles 

 from any Spanish settlements ; yet, during the many, many years 

 that the scattered Indians of this region have been trading with or 

 robbing Mexicans, they have passed from hand to liand, from tribe 

 to tribe, various luxuries of civilization, until they have penetrated 

 the most inaccessible portions of the interior. Peach stones are 

 easily transported, and, through the agricultural "Pueblo" Indians, 

 they have been generally disseminated over the table lands of New 

 Mexico and Arizona, as we subsequently often found peach trees 

 growing about springs along the routes of travel. 



Near the mouth of tlie Little Colorado we attempted, in the same 

 way as before, to penetrate to the bottom of the Great canon, but 

 this time without success ; for, though we descended nearly to the 

 river, and carried down a barometer to a point only 1,500 feet above 

 the level of the sea, then we were stopped by a precipice we could 

 not pass. The cliffs overlooking the canon of the Colorado at the 

 junction of the Little Colorado with that stream are, as we subse- 

 quently learned, 8,000 feet above the level of the sea ; and as the 

 river there is about 1,500 feet above the sea, the walls of the canon 

 are more than a mile in height. 



The canon of the Little Colorado we found utterly impassable, 



[Inst.] 19 



