The Cecil Whig. [volume] (Elkton, Md.) 1841-current, 1875-06-19

Our late cratic spring has provoked the
usual amount of comment and discussion,
yet we have failed to notice any attempt to
trace the causes of the persistent chiliness
of the air in the face of the suns manifest
power, or to account for the sudden sum-
mer heat of May.
Not that there has been any thing ex-
traordinary in the conditions of the weather
this year. Spring in our climate is always
an uncertain blending of winter and sum-
mer, each retaining much of its native
popularity; so that it is no uncommon
thing for morning mild as June to be fol-
lowed by snow storm in the afternoon, or
for an icy wind, piercing as an arctic blast,
to sweep the open country, while in shell
tered places the sun burns with midsum-
mer intensity. Such contrasts are tire
somely common, yet they never cease to
strike US as something abnormal. In spite
of our yearly experience to the contrary,
we persist in thinking that winters sever
ity ought to let up gradually; that the
transition from winter to summer ought to
be as gentle and uniform as the change
from summer to winter. Why it is not
and cannot be may be worth moments
thought.
1t is we'll known that one of the chief
factors of climate is the suns altitude.
The more nearly vertical its ways, the
greater it's power. The suns position,
however, is not the only factor. If it were,
February would be as mild as October,
April as hot as August. When under fav-
orable conditions we experience the swell
tering heat of the suns untempered rays
in spring time, we are apt to say that it
must be through contrast with the winters
cold that we feel the heat so keenly. But
we deceive ourselves. During the months
when winter fingers in the lap of spring,
the days are as long, the altitude Of the sun
is as great and the heating power of his
rays is as intense as in midsummer. Their
| failure to mitigate more rapidly the sever
| ity of the season is due to the simple fact
| that they have other work to do.
TO change pound of ice at 800 to water
| of the same temperature requires the ex-
penditure of 143 units of heat, each capa-
Bile of raising, when converted into mechau-
ical motion, pound weight 772 feet high.
In melting a pound of ice, therefore, more
than fifty foot tuns Of solar energy is
exhausted. Think what an incalculable
| amount of solar radiation is required to
melt the millions of tuns of ice and snow
every spring between this and Greenland!
During the fall months, immense amounts
of water are converted into ice in the north
ern hemisphere, setting free an enormous
amount of heat to reinforce the rays of the
declining sun, giving US an Indian summer
at season when the weather would be
coolest did the temperature depend upon
the sun alone.
This year, winter fingered unusually late,
and summer came with burst. The ice
in the lakes and rivers was uncommonly
thick, and the ground was covered with
deep snow. To convert this snow and ice
into water taxed the suns power, SO that
it was not until after it had reached the
northern tropic and was southwark bound
again that it began to gain on the wntry
weather. 1t will be remembered also that
| the greater part of the snow was not merely
melted, but evaporated. 1t disappeared
while we were anticipating disastrous floods
not through the rivers, but into the air.
Had the snow gone off in the form of
water, each pound of it would have ex-
hausted So foot tuns of solar energy. To
convert it into vapor required about seven
times as much, or 1921 foot tuns, that being
the mechanical equivalent of one pound of
water. In view of the vast amount of
snow and ice evaporated this spring, it is
not surprising that the approach of warm
weather was so dilatory. 1t was the price
we had to pay for exemption from floods
and freshets.
Having cleared the ground of snow and
snow water, the sun was free to give its
full force to the earth, which, in the alb
sence of the usual spring rains, was speed
lily put in condition to convert the suns
rays into heat for the warming of the air.
Consequently the interval was brief be-
tween reports of ice foes in the harbor and
sunStrokes in the streets.
| Scientific American