3rdly—They are the great store-houses of rain.
Q. Why is wind said to blow up the clouds?
A. When a dry wind travels over sea, and accumulates more vapour than the air can sustain, it relinquishes a part (as it flies along) in the form of clouds.
Q. Why does wind sometimes drive away the clouds?
A. When wind travels over dry climes or thirsty deserts, it becomes so dry itself, that it absorbs vapour from the clouds, and disperses them.
Q. What is the cause of a red sun-set?
A. Because the vapour of the air is not actually condensed into clouds, but only on the point of being condensed; in which state it bends the red rays of the sun towards the horizon, where they are reflected at sun-set.
Q. Why is a red sun-set an indication of a fine day to-morrow?
A. Because (notwithstanding the cold of sun-set) the vapours of the earth are not condensed into clouds. Our Lord referred to this prognostic in the following words: “When it is evening ye say, it will be fair weather, for the sky is red.” (Matt. xvi. 2.)