STEEP TRAILS 



of quiescence intervened between many dis- 

 tinct eruptions, during which the cooling lavas 

 ceased to flow, and took their places as perma- 

 nent additions to the bulk of the growing 

 mountain. Thus with alternate haste and 

 deliberation eruption succeeded eruption, until 

 Mount Shasta surpassed even its present sub- 

 lime height. 



Then followed a strange contrast. The gla- 

 cial winter came on. The sky that so often had 

 been darkened with storms of cinders and 

 ashes and lighted by the glare of volcanic fires 

 was filled with crystal snow-flowers, which, 

 loading the cooling mountain, gave birth to 

 glaciers that, uniting edge to edge, at length 

 formed one grand conical glacier a down- 

 crawling mantle of ice upon a fountain of 

 smouldering fire, crushing and grinding its 

 brown, flinty lavas, and thus degrading and 

 remodeling the entire mountain from summit 

 to base. How much denudation and degrada- 

 tion has been effected we have no means of 

 determining, the porous, crumbling rocks 

 being ill adapted for the reception and preser- 

 vation of glacial inscriptions. 



The summit is now a mass of ruins, and all 



the finer striations have been effaced from the 



flanks by post-glacial weathering, while the 



irregularity of its lavas as regards susceptibility 



34 



