Evening Republican, Volume 23, Number 120, Rensselaer, Jasper County, 18 May 1920 — WHEN THE CLOUDS GATHER [ARTICLE]

WHEN THE CLOUDS GATHER

"Birth” of - Thunderstorm, as Seen by Airmen, -Is a Remarkable and Beautiful Bpectacte. Have you ever been in the air to watch a" thunderstorm grow? asks Popular Mechanics Magazine. f If you were merely on the ground looking up, then you saw only the bottom of it. The* airman is the one who sees Just what is happening In a thunderstorm. A few hours before the sky was, perhaps, perfectly clear. All at once a few white patches become visible to the eye, and if they quickly begin to dot the whole sky, it is a 'warning sign. Each fluffy cloud represents the point where moisture rising from the earth has begun to condense. The rapid formation of the clouds means uneven heating of- the surface of the earth and the presence of lots of moisture In the air. The clouds grow together, forming a continuous polling mass of dense vapor, cutting off the flyer’s view of the earth. So far the storm has only been threatening. The clouds have spread sideways as far as they can; now they begin to grow heavier. The heated air from the earth below pushes through the heavy layer and bulges it upward. Higher and higher it is pushed while more and more raoistuse condenses, and this great bulging mass of vapor, sometimes three or four mildshigh, has become a thunder cloud. Its bulging tops 9 re called thuni’er peaks or thunder heads, and they ar« responsible for the lightning/ the heaviness of rainfall, and the hail we sometimes have in midsummer. The energy of a thunderstorm is amazing. A single great cloud may contain billions of pounds of water vaftor. The flashes of lightning from cloud to cloud are sometimes 20 miles in length, and vjjien we stop to think that it takes a current of 15,000 volts pressure to produce a spark an inch long, we can only wonder at the immense amount of electricity Involved in a single flash. Sometimes the wind from a thundercloud, or the squall, as it Is called, Is violent enough to level trees and small bulfdlngs, and is improperly called a tornado. There is a big difference. A tornado is a violent whirlpool -of air that sweeps across the country and twists off trees and roofs in its path. The wind from a thunderstorm blows straight away from the storm and never twists. Broadly speaking, there are three general stages in the development of a thunderstorm. There must, be strong currents of moist air rising from the earth, as indicated by the appearance of the white patches of cloud.- This condition must continue until the sky is covered. And lastly, the force of these upward currents must be great enough to push the clouds up into thunder heads. A thunderstorm then results.