Schlagintweit, Hermann von; Schlagintweit, Adolf; Schlagintweit, Robert von: Results of a scientific mission to India and High Asia: undertaken between the years MDCCCLIV and MDCCCLVIII, by order of the court of directors of the hon. East India Company (Band 4): Meteorology of India: an analysis of the physical conditions of India, the Himálaya, western Tibet, and Turkistan (Leipzig, 1866)

VI. THE YEARLY PERIOD OF TEMPERATURE.

The Seasons. Limits of rise and fall; the divisions of the natives.
Illustrating Views of the Atlas ; from the tropics.

Absolute Extremes. Data from the globe in general for comparison with the tropics.

THE SEASONS.

In the yearly period of the temperate zones of our hemisphere the temperature
begins to rise from the middle of January1 to the end of July or the beginning of
August, when it reaches its maximum; the change is more rapid in April and May.
and when decreasing, in September and October, than in the other months.

In the tropics of Asia, though on the same side of the Equator, the time of the
periodical rains has sufficient power to modify the direct influence of the height
of the sun; the hottest part of the year is the period before June, preceding
the rains, which, for the greatest part of India, coincide with our summer, includ-
ing June, July, and more or less of August. In the southern regions of India and
in Ceylon the rains are not so strictly limited to this part of the year only: here
rains in the months of the cool season become predominant. This, combined with the
double culmination of the sun separated by an interval of several months, materially
modifies the seasons and yearly range of temperature, as will be evident from a
comparison of the curves added to the plates of the isothermal lines.

1 In the Polar and Alpine regions February is colder than January. See "Physical Geography of the Alps,"
Vol. I., p. 359.

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