334 PHYSICAL GEOGRAPHY. 



the most minute objects were distinctly visible. Day broke very slowly, and the sun rose 

 of a fiery and threatening aspect. Rain followed. Captain Bonnycastle caused a bucket 

 of this fiery water to be drawn up ; it was one mass of light, when stirred by the hand, 

 and not in sparks, as usual, but in actual coruscations. A portion of the water preserved 

 its luminosity for seven nights. On the third night, the scintillations of the sea re- 

 appeared ; this evening, the sun went down very singularly, exhibiting in its descent a 

 double sun ; and, when only a few degrees high, its spherical figure changed into that of 

 a long cylinder, which reached the horizon. In the night the sea became nearly as lumi- 

 nous as before ; but on the fifth night, the appearance entirely ceased. Captain Bonny- 

 castle does not think it proceeded from animalcula, but imagines it might be some 

 compound of phosphorus, suddenly evolved, and dispersed over the surface of the sea ; 

 perhaps from the exuviae or secretions of fish connected with the oceanic salts, muriate 

 of soda, and sulphate of magnesia." 



In the region of the tropical calms, lying between that of the north and south steady 

 breezes, day after day is often passed without a whisper of the wind upon the deep, or the 

 flap of a sail, and the ocean has no movement but that of a long huge swell, like the heaving 

 chest of a giant in his sleep. But for the occasional occurrence of short squalls, the 

 passage of this region would be almost impossible to sailing vessels, and parts of Byron's 

 striking picture might soon be realised : 



" The rivers, lakes, and ocean, all stood still, 

 And nothing stirred within their silent depths ; 

 Ships, sailorless, lay rotting on the sea, 

 And their masts fell down piecemeal ; as they dropped, 

 They slept on the abyss without a surge. 

 The waves were dead ; the tides were in their grave ; 

 The moon, their mistress, had expired before ; 

 The winds were withered in the stagnant air, 

 And the clouds perished. " 



The squalls offer a brief but grateful interruptioa to the calms, and occur under singular 

 circumstances. Amid the scorching heat of noon, a cloud appears, generally in the east, 

 black and well-defined, when suddenly the wind springs up, blows violently for a few 

 minutes, suddenly subsides, and the calm returns. It is by the aid of these fitful gusts 

 that the passage of the tropical region of calms is effected. The ocean, in other parts of 

 the torrid zone, as quickly changes its aspect from that of a smooth shining mirror to a 

 surface shattered and tortuous, reflecting the hue of the black louring clouds ; and the 

 storm sometimes rages with violence for days together. Captain Hall describes one of 

 the tropical storms, when off the west coast of Mexico : "On the evening of the 24th of 

 February the sun set with astonishing splendour, but with a wild lurid appearance, which, 

 in any other country, would have put us more upon our guard. The sun itself, when 

 still considerably above the horizon, became of a blood-red colour, and the surrounding 

 clouds assumed various bright tinges of a fiery character, fading into purple at the zenith : 

 the whole sky looked more angry and threatening than any thing I ever saw before. 

 The sea was quite smooth, but dyed with a strange and unnatural kind of redness by the 

 reflection from the sky. In spite of the notions we held of the fineness of the climate, I 

 was made a little uneasy by such threatening appearances, and upon consulting the 

 barometer, which in these low latitudes is seldom of much use, was startled by finding it 

 had fallen considerably. This determined me immediately to shorten sail ; but before it 

 could be fully accomplished, there came on a furious gale, which split many of our sails, 

 broke our ropes like cobwebs, and, had it not been for great exertions, we might have 

 been dismasted. At length we got things put in proper trim to withstand the storm, 



