Chapter One 



HISTORICAL INTRODUCTION 



From the time of the recorded discovery of the Gulf Stream to the present 

 there have been many ideas about its cause. The historical references^ 

 I shall make will be restricted to those for M-hich some documentary 

 evidence exists — a plan that excludes a large body of speculation about 

 early Norse, Arabian, and Portuguese navigators. 



EARLY IDEAS AND EXPLORATIONS 



Although the island of Cuba was first circumnavigated in 1508, it was not 

 until 1513 that the Gulf Stream (specifically, the Florida Current) was 

 described by Ponce de Leon, who, sailing from Puerto Rico, crossed the 

 stream north of Cape Canaveral and then sailed south to Tortugas. The 

 current was so swift that his three ships were frequently unable to stem it 

 (see Herrera y Tordesillas, 1601). 



By 1515 Peter Martyr of Anghiera reported various conjectures about 

 the Gulf Stream (see the 1577 translation of his Decades). His arguments 

 were based essentially upon the principle of the conservation of mass and 

 upon the tacit assumption that the current velocity is independent of 

 depth. Peter Martyr argued that the North Equatorial Current must 

 either (i) pile up large masses of water at the BraziHan coast, or (ii) pass 

 through some great straits or passages into the Pacific and thence round 

 again into the Atlantic, or (iii) be deflected by the mainland so as to flow 

 back into the ocean (Kohl, 1868). The first possibiUty was ruled out, he 



1 The material in this chapter is drawn from an article by the author in the 

 Scientific Monthly for April, 1950. 



