36 



THE DESEKT 



the high table-lands sea-shells in abundance. 

 The petrified clams are precisely like the live 

 clams that one picks np on the western coast 

 of Mexico. The corals, barnacles, dried sponge 

 forms, and cellular rocks do not differ from 

 those in the Gulf of California. The change 

 from sea to shore, and from shore to table-land 

 and mountain, no doubt took place very slow- 

 ly. Just how many centuries ago who shall 

 say ? Geologists may guess and laymen may 

 doubt, but the Keeper of the Seals says noth- 

 ing. 



Nor is it known just when the porphyry 

 mountains were roasted to a dark wine-red, 

 and the foot-hills burnt to a terra-cotta orange. 

 Fire has been at work here as well as wind 

 and water. The whole country has a burnt 

 and scorched look proceeding from something 

 more fiery than sunlight. Volcanoes have left 

 their traces everywhere. You can still see the 

 streams of lava that have chilled as they ran. 

 The blackened cones with their craters exist ; 

 and about them, for many miles, there are 

 great lakes and streams of reddish-black lava, 

 frozen in swirls and pools, cracked like glass, 

 broken into blocks like a ruined pavement. 

 Wherever you go on the desert you meet with 



