A COLORADO SKETCH 23 



fitting field for observation. The mountain ranges 

 and extensive level spaces comprised within their 

 limits are important factors in the economy of 

 nature. The great masses of heat- radiating rock 

 temper the v^^inds that blow over them, and shed 

 genial warmth far and wide. The whole region 

 is one vast brewery of storms. Chemical changes 

 are constantly going on. Electricity is working 

 with exceptional vigour, riving the solid rocks, 

 devastating trees, and putting forth most vividly 

 the awful and mysterious manifestations of its 

 strength. Hot currents and cold currents fight 

 aerial battles round those patient peaks, that stand 

 unmoved amidst the roar and racket of elemental 

 strife. Frequent lightnings blaze or flicker round 

 the mountain heads ; continuous thunder crashes 

 on their slopes, and rolls and rumbles in the 

 caverns and valleys that seam their sides. Tem- 

 pests shriek roimd the crags, and moan dismally 

 as they toss the gnarled and matted branches of 

 the stunted trees that force their adventurous 

 way up the broad shoulders of the range. Snow 

 in winter, rain and hail in summer, pour upon the 

 higher summits ; while, beneath, the land is 

 glowing under a cloudless sky. Contending air- 

 currents of different density discharge their 



