e solar rays upon the surface of
the globe, along with the increased length of the day, mainly accounts
for the high temperature of summer as compared with that of winter.

Astronomically, the seasons commence at the periods of the equinoxes and
solstices. Spring begins on March 21, the time of the vernal equinox;
summer on June 21, at the summer solstice; autumn on September 22, at
the autumnal equinox; and winter on December 21, at the winter solstice.
This conventional division of the year is not equally applicable to all
parts of the globe. In the arctic and antarctic regions spring and
autumn are very brief, the summer is short and the winter of long
duration. In the tropics, owing to the comparatively slight difference
in the obliquity of the Sun's rays, one season is, as regards
temperature, not much different from the other; but in the temperate
regions of the Earth the vicissitudes of the seasons are more
perceptible and can be best distinguished by the growth of vegetation,
and the changes observable in the foliage of shrubs and trees. In spring
there is the budding, in summer the blossom, in autumn the
fruit-bearing, and in winter the leafless condition of deciduous trees,
and the repose of vegetable life.

The legendary belief that before the Fall there reigned on the Earth a
perpetual spring, is introduced by Milton in his poem when he describes
the pleasant surroundings associated with the happy conditions of life
that existed in Paradise:--

Thus was this place,
A happy rural seat of various view:
Groves whose rich trees wept odorous gums and balm;
Others whose fruit, burnished with golden rind,
Hung amiable--Hesperian fables true,
If true here only--and of delicious taste.
Betwixt them lawns, or level downs, and flocks
Grazing the tender herb, were interposed,
Or palmy hillock; or the flowery lap
Of some irriguous valley spread her store,
Flowers of all hue, and without thorn the rose.
Another side, umbrageous grots and caves
Of cool recess, o'er which the mantling vine
Lays forth her purple grape, and gently creeps
Luxuriant; meanwhile murmuring waters fall
Down the slope hill dispersed, or in a lake
That to the fringed bank with myrtle crowned
Her crystal mirror holds, unite their streams.
The birds their quire apply; airs, vernal airs,
Breathing the smell of field and grove, attune