PHENOMENA IN THE INTERIOR. 205 
ary and the beginning of March the blue of the sky 
is less intense; the hygrometer gradually indicates 
greater humidity ; the stars are sometimes veiled 
by a thin stratum of vapours ; their light ceases to 
be tranquil and planetary ; and they are seen to 
sparkle from time to time at the height of 20° above 
the horizon. At this period the breeze diminishes 
in strength, and becomes less regular, being more. 
frequently interrupted by dead calms. Clouds ac- 
cumulate towards the south-east, appearing like dis- 
tant mountains with distinct outlines. From time 
to time they are seen to separate from the horizon, 
and traverse the celestial vault with a rapidity which 
has no correspondence with the feebleness of the 
wind that prevails in the lower strata of the air. 
At the end of March the southern region of the at- 
mosphere is illuminated by small electric explosions, 
like phosphorescent gleams confined to a single group 
of vapours. From this period the breeze shifts at 
intervals, and for several hours, to the west and 
south-west, affording a sure indication of the ap- 
proach of the rainy season, which on the Orinoco 
commences about the end of April. The sky begins 
to be overcast, its azure colour disappears, and a gray 
tint is uniformly diffused over it. At the same time 
the heat of the atmosphere gradually increases, and 
instead of scattered clouds the whole vault of the 
heavens is overspread with condensed vapours. The 
howling-monkeys begin to utter their plaintive 
eries long before sunrise. The atmospheric electri- 
eity which, during the period of the greatest drought, 
from December to March, had been almost con- 
stantly in the daytime from 1-7 to 2 lines to Volta’s 
electrometer, becomes extremely variableafter March. 
