russeli..] CLIMATE. 21 
slopes on which every line etched through centuries by rills and 
creeks reveals its history. The mountains seemingly grow in stature 
and unfold ridges and buttresses separating profound depths. One 
marvels at the diversity and strength of the sculpturing on what but 
a few moments before appeared flat, meaningless surfaces. 
As the sun sinks lower there are, perhaps, a few clouds near at 
hand which are seemingly burned or rendered molten by the intense 
heat, but more frequently only a nebulous glory appears in the vapor- 
less air. The violet and purple shadows creep higher and higher on 
the mountain slopes, and at last each crest and pinnacle, still sharply 
outlined, becomes but a shadow. During the cloudless summer the 
glories of sunset are on the earth, not in the sky. As the sun disap- 
pears a well-defined twilight arch arises in the east, the shadow of the 
earth on the dust particles in the air. The upper margin of the arch 
is at first well-defined, but fades as it rises and is lost when the stars 
begin to gleam in the dark heavens. The cool, star-lit summer nights 
are wonderfully magnificent. The heavens, without a cloud, are filled 
from horizon to zenith with stars which burn with a steady planetary 
light, such as is seen in our eastern humid kinds only during clear 
winter weather. 
Although the summers in southern Idaho, in common with the rest 
of the great arid region of which it is a part, are characteristically 
cloudless, sometimes completely so for many days and even a week or 
two, yet as fall approaches vapor banks appear and the glory in the 
heavens and the magnificence of the earth increase a thousand fold, 
surpassing the ability of even a poet to describe. One feature of the 
weather in early fall is the gathering of thunder storms about the 
mountains and their advance with fierce lightning and deep-toned 
thunder over the plains, where they melt away and disappear ineffec- 
tually in the drier air. At times these struggles of opposing forces are 
repeated daily, and a more advanced position is gained each afternoon 
by the invading storm, until a few pattering rain drops fall, or per- 
chance a brief drenching downpour occurs on the thirsty sagebrush 
lands. More often, however, the vast banks of brilliantly illuminated 
cumulus clouds are festooned below with descending rain sheets 
which fail to reach the earth. Accompanying these inefficient thun- 
der squalls there sometimes comes a heavily dust-laden wind which 
advances across the land like a wall of blackness, obscuring the land- 
scape, and as it passes the observer producing a twilight even when 
the sun is high in the heavens. At such times the eyes are blinded 
and the throat is choked by the all-penetrating dust particles. These 
dust storms, unaccompanied by rain, explain the origin of the fine 
yellow soil which covers much of the plains, mantles the sides of iso- 
lated volcanic hills, and extends far up the neighboring mountain 
slopes. 
