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WIND AND WEATHER. 
By The BISHOP OF BURNLEY (Dr. HENN). 
November 15 th, 1909. 
The phenomena of wind and weather are due to the state 
of that great blanket which surrounds the earth, the atmos- 
phere. The movements of the atmosphere, its temperature, 
and the amount of moisture it contains, are the sole conditions 
which go to form wind and weather. 
The combination of gases which forms the air we breathe 
always contains invisible moisture. This atmosphere has 
great elasticity and considerable weight, and envelopes the 
earth to a thickness of some 45 miles. Its density is not 
uniform, being greatest near the earth’s surface and becoming 
gradually rarefied towards its outer circumference. The 
weight of the atmosphere is measured by the barometer. 
Wind, whether a gentle zephyr or a roaring tempest, is 
simply the atmosphere in motion. In a strong wind the air 
travels at about 30 miles an hour, in a gale at about 50, in a 
strong gale at 60 or 70, and in a hurricane at 80 or 90. Nor- 
mally the atmosphere is inert as all other bodies are until 
some force is applied. The force which causes the atmosphere 
to move and creates wind is the application of heat. When 
air is heated it expands, becomes lighter in proportion to an 
equal volume of the surrounding cold air, rises in consequence, 
and is displaced by the colder air which by its inrush makes 
a wind. The sun, the source of all natural heat, is thus 
the creator of winds. The simplest and most constant example 
of its action is the regular daily alternation of landward and 
seaward breezes upon an island. The air is warmed but little 
by the passage through it of the sun’s rays, taking most of 
its heat from contact with the heated earth. The earth is 
both heated and cooled more quickly than the sea. At 
