i 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 



