dust of ages blown from the Mongolian plateau. The passage from north
to south is generally from the older to the newer rocks; from east to
west a similar series is found, with some volcanic features in the
west and south. Coal and iron are the chief minerals, gold, silver,
copper, lead, tin, jade, etc., being also mined.

The climate of this vast area is not uniform. In the north the winter
is long and rigorous, the summer hot and dry, with a short rainy season
in July and August; in the south the summer is long, hot, and moist,
the winter short. The mean temperature is 50.3° F. and 70° F. in the
north and south respectively. Generally, the thermometer is low for
the latitude, though perhaps it is more correct to say that the Gulf
Stream raises the temperature of the west coast of Europe above the
average. The mean rainfall in the north is 16, in the south 70 inches,
with variations in other parts. Typhoons blow in the south between
July and October.


Organic Environment

The vegetal productions are abundant and most varied. The rice-zone
(significant in relation to the cultural distinctions above noted)
embraces the southern half of the country. Tea, first cultivated
for its infusion in A.D. 350, is grown in the southern and central
provinces between the twenty-third and thirty-fifth degrees of
latitude, though it is also found as far north as Shantung, the chief
'tea district,' however, being the large area south of the Yangtzu
River, east of the Tungting Lake and great Siang River, and north of
the Kuangtung Province. The other chief vegetal products are wheat,
barley, maize, millet, the bean, yam, sweet and common potato, tomato,