1 CLIMATE AND ASPECTS OF THE EQUATORIAL ZONE 233 
that of the tropics. Even with us the duration of twilight 
is very much shorter at the time of the equinoxes, and 
it is probably not much more than a third shorter than this 
at the equator. Travellers usually exaggerate the short- 
ness of the tropical twilight, it being sometimes said that if 
we turn a page of the book we are reading when the 
sun disappears, by the time we turn over the next page 
it will be too dark to see to read. With an average book 
and an average reader this is certainly not true, and it 
will be well to describe as correctly as we can what really 
happens. 
In fine weather the air appears to be somewhat more 
transparent near the equator than with us, and the intensity 
of sunlight is usually very great up to the moment when the 
solar orb touches the horizon. As soon as it has disappeared 
the apparent gloom is proportionally great, but this hardly in- 
creases perceptibly during the first ten minutes. During the 
next ten minutes, however, it becomes rapidly darker, and at 
the end of about half an hour from sunset the complete darkness 
of night is almost reached. In the morning the changes are 
perhaps even more striking. Up to about a quarter past five 
o’clock the darkness is complete; but about that time a few 
cries of birds begin to break the silence of night, perhaps 
indicating that signs of dawn are perceptible in the eastern 
horizon. A little later the melancholy voices of the goat- 
suckers are heard, varied croakings of frogs, the plaintive 
whistle of mountain thrushes, and strange cries of birds or 
mammals peculiar to each locality. About half-past five the 
first glimmer of light becomes perceptible ; it slowly becomes 
lighter, and then increases so rapidly that at about a quarter 
to six it seems full daylight. For the next quarter of an 
hour this changes very little in character ; when, suddenly, the 
sun’s rim appears above the horizon decking the dew-laden 
foliage with glittering gems, sending gleams of golden light 
far into the woods, and waking up all nature to life and- 
activity. Birds chirp and flutter about, parrots scream, 
monkeys chatter, bees hum among the flowers, and gorgeous 
butterflies flutter lazily along or sit with fully expanded 
wings exposed to the warm and invigorating rays. The first 
hour of morning in the equatorial regions possesses a charm 
