158 On the Campus 



sometimes deep buried by vast deposits of wine-red marls 

 and clays, or covered anon by the products of erosion, 

 whether by water or by wind. The waters from the 

 mountain snows have brought their debris; the winds of 

 the desert have come with their burden, but nowhere has 

 such transportation traversed the desert borders, at least 

 in recent times; there are to-day no excurrent nor per- 

 current streams; the winds die along the mountain walls 

 and the waters sink in the desiccated sands. 



But this is not all. This great sunken block of earth's 

 crust seems itself to have been cracked again and again ; 

 there are secondary faults, and along the line of one of 

 these thinner or weaker places the subterranean energies 

 of the world have some time found emergence. Floods 

 of lava welled up in the midst of the desert, and foun- 

 tains of fire streamed along the ground, following exis- 

 tent topography for miles and miles, now narrowing to 

 dimensions measured by rods between low ranges of hills, 

 now widening for miles across the broader valleys, only 

 to lie at last a vast field of blackened cinder, slowly dis- 

 integrated by the desert storms. This is one of the most 

 peculiar topographic features of the whole desert. As 

 things terrestrial go, this is a recent phenomenon. The 

 age of lava may be measured by centuries, a few thou- 

 sand years, it would seem, at most. The surface over 

 which it poured was a friable, marly soil. As the floods 

 cooled, the mass cracked and gaped in every direction. 

 Rains descending upon the surface sank to the ground 

 below and shaped for themselves channels. The lava so 

 undermined has fallen into a tumbled mass of weirdness 

 and confusion, indescribable, impassable. 



