Page:Weather Facts and Predictions.djvu/24

 heat can ascend from the soil below to counteract the cold on the surface, and so the temperature falls considerably.]

It is much hotter in the interior of such continents in summer than at the Western borders. [Because the land being warmer than the ocean at this season, the wind becomes warmer as it traverses the land, and the superjacent air being drier, the rays of the sun act with an intensity which is always more or less excessive.]

Wind blows from regions where the barometer is high to where it is low, and with a force proportioned to the difference of the pressures, and places between very high and very low pressures feel most the violence of the resulting storm, and not those where the pressure is absolutely the lowest.

If the wind being N. passes to N.E. we get clear weather; the air is dry, the barometer high, and in winter a considerable degree of cold follows. If the wind gets on to the E. the barometer will fall, and the sky become more or less overcast. Snow and S. wind may then be expected. If the barometer falls rapidly, the snow will turn to rain, and a thaw set in if the wind veers farther, through S.E. and S. to S.W.

If a N.E. wind be accompanied in winter by a clear sky, with haze near the horizon, and the barometer be high and rising, or at least stationary, and the wind does not increase in force but tends to change in the direction of E. and S.E. the weather will probably continue settled for some time.

One of the surest signs of the breaking up