THE GULF STREAM. 251 



or the Mona Passage, until they reach the belt of variable and 

 westerly winds, when they steer toward the European shores 

 again. 



After reaching the Mexican coast, Columbus, by one of his 

 broad generalizations, practically discovered the Straits of Flo- 

 rida ; arguing that it must have an outlet into the Atlantic, and 

 that he would thus escape the tedious voyage in the teeth of 

 the northeast trades, which would be his lot if he attempted to 

 find his way home by the usual route of the Windward or the 

 Mona Passage. In 1519, an expedition inspired by Alaminos 

 was despatched by Garay, Governor of Jamaica, to follow the 

 easterly current running along the northern shores of Cuba. 

 The expedition, however, did not succeed in passing to the east- 

 ward of Cape Florida. 



An accurate knowledge of the currents and winds enabled 

 the freebooters of the sixteenth century to carry on their depre- 

 dations with impunity, and then* successors, thie wreckers of the 

 Florida reefs and Bahamas, made use of their intimate know- 

 ledge of the coasts, and of the winds and currents, to obtain 

 commercial advantages, not always by the most honest methods. 

 With the mapping of the reefs by the Coast Survey all this has 

 disappeared, and the lighting of the great highway of the 

 Straits of Florida has reduced to a minimum the dangers of 

 navigation, though the Tortugas are still a favorite resort, even 

 in broad daylight, for old ships properly insured. (Compare 

 Figs. 172 and 34.) 



The captain of one of the Spanish vessels was carried south, 

 off the coast of South America, by the current which sweeps 

 from Cape St. Roque along the shores of Brazil, and involunta- 

 rily discovered the Brazilian shore current. Though these dif- 

 ferent currents were known to exist in the Atlantic, the most 

 crude notions of their origin and course prevailed. (Fig. 172.) 

 According to Columbus, at the equator the waters of the ocean 

 moved westward with the heavens above, rolling over the fixed 

 earth as a centre. It was only in the seventeenth century that 

 physicists began to suspect a connection between the currents 

 and the rotation of the earth, a view afterwards maintained by 

 Arago and Humboldt. 



