New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1875-02-20
HEATHER SPECUL4TIONS.

a
and higher in the heavens with the advancing
year. we naturally hope that each one OF the
long series of cold atmospheric waves that roll
over the continent will close the season OF
these unwelcome visitors. 1t is safest, how
| ever to base no prophecies upon such hopes,
| since in this matter not even the Signal
Service can give the probabilities beforehand.
The courses of tho winds, the changes of the
sky, the varying of the seasons, have In oil
climes and ages furnished the poet and the
moralist with fit Illustrations of mans lgnor-
| ance and of the incomprehcns,be power that
! surrounds him. Until within q few yeals 1t
has remained as true as when it was written,
that tho wind blOweth where it listeth, and
we know not whence it cometh or whittier it
goeth. Nor is it yet safe for us to say that
eve have changed all that" We are indeed
much better able than formerly to trace the
course of storm and wind, but are only
little more prepared to state their ultimate
| origin.
EXCEPT as regards the ordinary succession
of the seasons astronomical periods have
very little to do with the weather Many or
them arc too long to be tested by the expert
ence of individual life, or even by the records
of mans history. 1t is supposed, for Instance
and frequently referred to in hot weather
though the testimony is exceedingly doubtful
that the earth is approaching the sun. his
would be measured by the shortening of the
year. If there be such Shortening it is cal
culated as not efccting O reduction OF the
year by moro than second in century.
| The theory of the shifting of the earth's poles
may serve for another instance. This theory,
if correct, may or may not serve to account
for the extension of ice-felds over the tenn
| perate zones at tho glacial epoch, or for the
tropical warmth of those zones in the tertiary
age, when on the shores of vast and nameless
lakes near the Rocky Mountains, threc-toed
horses trod, while the six-horned head OF the
dnoceras came crashing through the jungle. But
no such secular change as that theory affords,
requiring period of at least 10000 years for
| it's cycle, will account for our present expert
ences, or explain why Winter that proved
unsatisfactory to ice companies and the pro-
prietors of skating Kinks, should be succeeded
by one that has thrown temporary bridges
over the Sound and tho Hudson. The answer
to the problem, if given at all, must be sought
in far different direction. Prof. Pliny Z.
Chase has summed up tho current view in tho
following words "The principal elements of
general thermOmetric variation are ID the
heat impaired by the sun; (2) terrestrial
absorption and radiation; (3) atmospheric
| currents. OF these three agencies, the first
"is in one sense at least, the chief since it is
:" the one on which the Others depend"
Our atmosphere is fluid of unstable equi-
| librium. Whenever any part OF 1t Is dis
placed, rising when expanded by heat or
| falling when contracted by cold. the surround
| ing air rushes to fill the vacuum. Thus the
heat that the sun dispenses below the trOpic
of Cancer may start cold breeze from above
Lake Michigan. While remarkable uniform
ty characterzes the winds of the equatorial
regions, our own present an apparently law
less variety, and we have yet much to learn
| respecting them. There is reason for belIev-
! ing that they arc closely related to changes
on the surface of the sun. 1t is known
| that the temperature of sun-spots is lower
than that of the surrounding photosphere,
| and the spectroscope has shown that they are
more condensed, and are probably clouds of
| metallic Stag. They are often OF immense
size; our whole continent if tumblcd into one
| of them might not touch the edges. Some
| times they last for several days, sometimes
| only few hours. Nothing that we know of
| in the universe, except comets tails, grows
more rapidly than sun-spot; and when the
plotosphere flows over it, its disappearance is
as speedy as its growth. The presence or
| absence of sun-spots must occasion great
variations in the heat sent US from the sun.
| A long series of statistics of observations on
sun-spots and on the movements of the
magnet during what are called magnetic
'storlns," has proved beyond doubt an init
mate connection between them. very able
essay by Mr.. Balfour Stewart, in a recent
number Of Nature, gives cOgent reasons tor
believing that these magnetic disturbances arc
largely due to movements in the upper at
mosphere of the earth, which must DO traced
in turn to variations in that Of the sum- We
| found occasion some months ago to comment
in these columns upon the remarkable coinci-
dences that have been found by Mr.. Meldrum
and other observers between the periods OF
sun-spot disturbance, of cyclones. and Of rain
fall, when tho greatest and least years OF
these phenomena are compared. In short, all
recent evidence tends to somewhat similar
conclusions on these points We shall not be
far wrong if we attribute Winters storms Us
we'll as Summers heats, to the glowing fur
| mace ut the center of our solar system.
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| ACTORS AND HUMAN BEINGS.