One afternoon we saw rolling masses of cumulus clouds rising above the far blue ridges; then as they drifted nearer the bright green of the forest made a background which brought out in relief their finely modeled forms.
"See America First"
Orville O. Hiestand
Dense cumulus clouds have formed, the upper surfaces of which have caught all the sun's heat, intensifying the unstable equilibrium of the air.
"Plotting in Pirate Seas"
Francis Rolt-Wheeler
When wearied with the romance of wild tropic scenes such as these, we have but to lift our eyes to the great mountain tops looming darkly and grandly on our right; to watch the light pencilling of the cirrus, brushing their summits, as it is drifted toward the north by the rising wind: to watch the changing forms which the clouds assume, from the fleecy horizontal bars of the cirrus, to the denser, gloomier cumulus, prognosticator of storm and rain, which soon settles into a portentous group-Alps above Alps, one above another-and we know the storm which was brewing is at hand, and that it is time to seek shelter.
"How I Found Livingstone"
Sir Henry M. Stanley