Page:Weather Facts and Predictions.djvu/29

 If (towards sunset especially) the sky clears on any part of the horizon the wind will shortly blow from the quarter cleared.

When the sea gets rough on a flood tide it is a sign of more wind coming [S. coast of England.]

When ozone is largely present in the air, it is accompanied by diminished pressure, increasing temperature and humidity, and a prevalence of S.W. or Equatorial winds. But when it is present only to a limited extent, the pressure is increasing, the temperature and humidity decreasing, and the prevailing wind is N.E. or Polar in character.

Ozone is more abundant on the sea coast than inland, in the West of Great Britain than in the East, in elevated than in low situations, in rural districts than in towns, and on the windward than on the leeward side of towns. Its amount seems to increase and decrease with the electricity, and it is almost wanting in places where there is much decaying vegetable or animal matter.

Ozone is most abundant in May, least so in November.

An attentive consideration of the changing tints of the evening sky after stormy weather furnishes valuable aid in forecasting the weather. If the yellow tint becomes a sickly green, more rainy and stormy weather may be expected, but if it deepens into orange or red the atmosphere is becoming drier, and fine weather will follow.