Water, when it is in an unfit condition for use, may be dangerous. When it falls from a cloud it is usually of a clear, light grey, but sometimes dark grey, and it always disappears after a few seconds. It is of importance to determine the state of the atmosphere before doing anything to avoid accidents.
The raindrops must not be too dense or too dilute. The density of the air should be able to bear the weight of the raindrops. If the rain is too heavy, water strikes the earth so strongly that the earth is lifted upward and carried along by the wind.
If the rain does not fall slowly and uniformly, it causes clouds and evaporation to rise to the surface. The cold air is forced back into the clouds which condense and fall as rain. If the rain keeps rising, a thunderstorm is formed.
If the rain falls on a sunlit hillside and is in contact with a warmer air layer, it is condensed. The clouds are forced to rise and pass over the sun where they remain for a time in the hotter air. If they do not rise again, they condense on the colder upper air and precipitate as rain.
If the rain falls while there is still a warmer air layer above, the rising clouds cannot pass over the sun and it gives place to another kind of atmospheric condition. The air below the cloud becomes agitated and is forced upward so that the rain falls all at once without being condensed at all.
In all weather conditions, if it is too dry, the rain simply falls off the clouds. The rain falls as drops of a specific size, varying with temperature and pressure.
If the rain is hot, the drops are so small that they boil off. If the rain is cold, the drops are so large that evaporation can take place. The ratio between the two extremes is regulated so that on the whole the water does not boil or evaporate.
But the conditions of the air are not the only considerations which should be taken into account. The other things which should be considered are the mechanical properties of the rain.
This depends on the physical properties of the water. Water is composed of two parts, oxygen and hydrogen. They have the same atomic weight.
The former is more common than the latter. The normal proportion of the two is approximately 4 to 1. (For example, water is 68% hydrogen.)
If the proportion is much greater than this, the 0b46394aab