Willows and lilac bring again
With the whistle of returning birds.”
Since the rain plays such an important role in nature’s plans, certain facts concerning its origin, and the clouds which govern its formation and fall, will prove of interest.
The prior causes of rain are due to the evaporation of moisture which is constantly going on, from ocean, lake and river, and all vegetation; until the air is freely saturated with moisture thus evaporated. Then “Mother Nature” assists, causing turbulent, driving winds to rise, and all her elements combine forthwith, to precipitate the moisture; and then follows the rain.
The rays of the sun falling upon the air stratum nearest the earth cause it to arise and expand. Thus, as a result, the clouds are formed. The ascending air leaves a partial vacuum below, which causes surrounding air to rush inward; which in turn causes winds. Once this process starts, it tends to grow and perpetuate itself. The inrushing air below forces the rising air still higher and higher, which causes dense clouds to form and rush upwards to great heights. Both snow and rain fall as a result of warm moist air being forced upward to a great altitude, and its moisture condensed.
The smaller raindrops fall from the lower cloud strata, but the larger drops descend from a much higher altitude. In the higher, frigid altitudes where snow, and the granular snow pellets are formed and exist, in the upper sections of the clouds; by falling down through the vast cloud regions below, they gradually collect minute cloud particles, and smaller drops in their travels, and thus, by melting, as they encounter warmer air currents, form the very large, high-altitude raindrops.
141 a. Coral-like branch showing the “feather type” in detail
141 b. Window-pane ice. Two forms, the arborescent and feather types