heights, their flanks and summits gleaming with sunlight, 
their nether surfaces above the desert as flat as a ceiling, 
and showing, not the dull neutral gray of the east, but a 
rosy tinge caught from the reflected red of rocks and soil. 
As they drifted rapidly against the great barrier, the cur- 
rents from below, flung upward to the summits, rolled the 
vaporous masses into vast whorls, wrapping them around the 
towers and crest-lines, and scattering tern shreds of mist 
'along the rock-faces. As the day wore on the sunshine gained 
the advantage. From overhead the cloud -masses stubbornly 
withdrew, leaving a few broken ranks to maintain a feeble 
resistance. But far in the northwest, over the Colob, they 
rallied their black forces for a more desperate struggle, 
and answered with defiant flashes of lightning the inces- 
sant pour of sun- shafts. 
Superlative cloud effects, common enough in other coun- 
tries, are lamentably infrequent here; but, when they do come 
their value is beyond measure. During the long, hot summer 
days, when the sun is high, the phenomenal features of the 
scenery are robbed of most of their grandeur, and cannot 
or do not who 11 y reveal to the observer the realities which 
* 
render them so instructive and interesting. There are few 
middle tones of light and shade . The effects of foreshort- 
ening are excessive, almost beyond belief, and produce 
the strangest deceptions. Masses which are widely sepa- 
rated seem to be superposed or continuous. Lines and 
