The Washington times., 1894-04-22
Prof. Harrington Discusses
Certain Signs of Spring.

The retreat of Winter before advancing
Spring has so much of poetical and practical
interest that it is worth while to study its de-
tails, but in orderto do this d definition of the
beginning of Spring must be adopted. For
this purpose the movement of animals or the
awakening and development of plants is
sometimes adopted; but, unfortunately. the
return of the swallows, the passage of the
wild geese northward, the movements of
other migratory birds and of alternating ami
mails, are not invariable accompanimen,s of
the appearance of Spring, whatever may be
thought of the infallibIlity of instinct.
A better criterion would be the awakening
OF plants, which does not depend on instinct
but upon physics and physiology; but here the
difference in behavior of different species. and
of the same species in different localities
makes it difficult to decide what phenomenon
OF what species, and in what place, should be
selected. The English violet takes advantage
Of every short respite of Winter to open its
buds. The crocus and other plants push up
their flowers through the snow. The swamp
maple develops its leaves early and rapidly
and most so in warm places and at the top Of
the tree, while the oaks, the tulip tree,
and the walnut are tardy in thus ac-
knowledging the arrival of warm weather.
A more practical criterion for the advent of
Spring can be found in the temperature on
which this advent depends. 1t is the sheat
that causes the SHOWS to disappear and physi-
ological life to awaken in the plant or to be-
come once more active in the animal, and it is
the increasing warmth which persuades the
migratory BIRDS who set the fashion of sea-
sonal change OF residence long before it was
adopted by mankind, to pass northward to
build their homes
Botanists state that the temperature of 6
degrees Centigrade, or 1873 degrees Fahren-
I..ts sr hot naah
tents Of the vegetable cell find the limits of
their activity. When the temperature falls
below this point the protoplasm becomes mac
tive, though it is not dead until the fall is from
several to many degrees lower. depending on
the species of the plant. When the tempera-
ture rises and reaches this point the proto-
plasm awakens, and as it passes above 49, s
degrees Fahrenheit the cells begin to grow
and multiply.
The advent of Spring may therefore prop
erly be considered as taking place at the ad-
vent OF the isotherm OF 43.S degrees Fahren-
heit. But the isotherms of warm weather in
any Spring do not advance and remain, but,
like the wavelets of an incoming tide they
advance and again retreat. though never GO
ing back quite so far as the point from which
they started. Each wavelet makes distinct
gain on the beach, and though the actual
waters edge seems always advancing and re-
treating, the tide itself is steadily advancing
The fluctuations are superficial, and can
be eliminated by the proper arithmetical
treatment. In the same way the isotherm of
43.S degrees, like any other, advances in a
huctuating way, but nevertheless gains some
ground at each fuctuation. These fuetua-
tions can likewise be disposed of by taking
the mean for many years. Although the
result will not show the actual advance in
any one season, it will bring out the average
advent OF the isotherm chosen, and will truth
yap featu of
From "The Advent of Spring. by Mark w.
HARRINGTON in Hnrnar's