While these figures may be taken to represent the aver-
age daily heat throughout Middle Egypt — ^itself nearly a
mean of the whole country — the night temperature is
from 8° to 12° lower, the fall rapidly following sunset and
continuing tUl sunrise. HygrometricaUy, the four months
of December, January, February, and March, over which
Nile tours generally extend, compare with our English
summer months of June, July, and August as about 56 to
81 ; and, generally, the humidity of the atmosphere varies
with the winds, being greatest when the wind is W. to
NE., less when it is FW. to E., and least of aU when S.
to SW. It need hardly be said that frost and snow
are almost unknown. Hailstorms, descending from the
Syrian hUls and sweeping across Palestine, sometimes
reach the Egyptian frontier, and Consul Stanley reports
having seen thin ice on the pools near Suez, but these are
rare incidents which happen only once or twice in a
century.
Like nearly all physical phenomena in Egypt, the
course of the wind, so variable in our climate, is there
almost strictly periodical. In point both of force and dura-
tion, the northerly breezes predominate, blowing nearly
nine months out of the twelve.* They continue with



* And thence anciently called " Etesian.'



340 EGYPT AS IT 18.
