XC1V NOTES. 



C 440 ) p. 285. Leonardo da Vinci says very finely of this proceeding, "questo 

 e il methodo da osservarsi nella ricerca de' fenomeni della natura." See Ven- 

 turi, Essai stir les Ouvrages physico-mathematiques de Leonard da Vinci, 1797, 

 p. 31 ; Amoretti, Memorie storiche su la Vita di Lionardo da Vinci, Milano, 

 1804, p. 143 (in his edition of the Trattato della Pittura, T. xxxiii. of the 

 Classici Ttaliani) ; Whewell, Philos. of the Inductive Sciences, 1840, Vol. ii. 

 p. 368370 ; Brewster, Life of Newton, p. 332. Most of Leonardo da 

 Vinci's physical works belong to the year 1498. 



( 441 ) p. 286. The great attention paid by the early navigators to natural 

 phenomena may be seen in the oldest Spanish accounts. Diego de Lepe, for 

 example, (as we learn from a witness in the law-suit against the heirs of 

 Columbus,) by means of a vessel provided with valves, which did not open 

 until it had reached the bottom, found that at a distance from the mouth of 

 the Orinoco, a stratum of fresh water of 6 fathoms depth flowed over the salt 

 water (Navarrete, Viages y Descubrim. T. iii. p. 549). Columbus, on the 

 south of the coast of Cuba, took up milk-white sea-water (" white as if meal 

 had been mixed with it") to be carried to Spain in bottles (Vida del Almi- 

 rante, p. 56). T was myself at the same spots, for the purpose of determining 

 longitudes, and was surprised that the milk-white discolouration of sea- water, 

 so common on shoals, should have appeared to the experienced admiral a new 

 and unexpected phenomenon. In what relates to the gulf-stream itself, which 

 must be regarded as an important cosmical phenomenon, various effects pro- 

 duced by it had been observed, long before the discovery of America, by the 

 sea washing on shore at the Canaries and the Azores stems of bamboos, trunks 

 of pines, corpses of foreign aspect from the Antilles, and even living men in, 

 canoes " which could not sink." But all this was then attributed solely to 

 the strength of westerly tempests (Vida del Almirante, cap. 8 ; Herrera, Dec. 

 i. lib. i. cap. 2, lib. ix. cap. 12) ; there was as yet no recognition of the 

 movement of the waters which is independent of the direction of the wind, 

 viz. the returning stream of the oceanic current, which brings every 

 year tropical fruits from the West India Islands to the coasts of Ireland and 

 Norway. Compare the Memoir of Sir Humphrey Gilbert, On the Possibility 

 of a North-west Passage to Cathay, in Hakluyt, Navigations and Voyages, 

 Vol. iii. p. 14 ; Herrera, Dec. i. lib. ix. cap. 12; and Examen crit. T. ii. p. 

 247257, T. iii. p. 99108. 



t 442 ) p. 287. Examen crit. T. iii. p. 26 and 6699 ; Kosmos, Bd. i. S. 

 823 and 330 (Engl. ed. Vol. i. p. 801 and 303). 



