FIRST USE OF THE LOG. 57 



Ptolemy, wo find that north of Greenland (Gmentlant), 

 which is represented as belonging to the eastern portion of 

 Asia, the north magnetic pole is depicted as an insular 

 mountain. Its position was gradually marked as being far- 

 ther south in the Breve Comjiendio tie la Sphera, by Martin 

 Cortez, 1545, as well as in the Geographic* di Tolomeo y of 

 Liveo Sanuto, 1588. The attainment of this point, called 

 el calamitico, was associated with great expectations, since it 

 was supposed in accordance with a delusion, which was not 

 dissipated till long afterward, that some miraculoso stupe ndo 

 effetto would be experienced by those who reached it. 



Until toward the end of the ICth century men occupied 

 themselves only with those phenomena of variation which 

 exerted a direct influence on the ship's reckoning and the de- 

 termination of its place at sea. Instead of the one line of no 

 variation, which had been found by Columbus in 1492, the 

 learned Jesuit, Acosta, who had been instructed by Portu- 

 guese pilots (1589), expressed the belief, in his admirable 

 Historia Natural de las Indias, that he was able to indicate 

 four such lines. As the ship's reckoning, together with the 

 accurate determination of the direction (or of the angle 

 measured by the corrected compass), also requires the dis- 

 tance the ship had made, the introduction of the log, al- 

 though this mode of measuring is even at the present day 

 very imperfect, nevertheless marked an important epoch in 

 the history of navigation. I believe that I have proved, al- 

 though contrary to previously adopted opinions, that the first 

 certain evidence of the use of the log* (la cadena de la popa, 

 la corredera) occurs in the journal which was kept by An- 

 tonio Pigafetta during the voyage of Magellan, and which 

 refers to the month of January, 1521. Columbus, Juan de 

 la Cosa, Sebastian Cabot, and Vasco de Gama, were not ac- 

 quainted with the log and its mode of application, and they 



* Cosmos, vol. ii., p. 256-258. In the time of King Edward III. of 

 England, when, as Sir Harris Nicolas (History of the Royal Navy, 

 1847, vol. ii., p. 180) has shown, ships were guided by the compass, 

 which was then called the sail-stone dial, sailing -needle, or adamant, 

 we find it expressly stated in the accounts of the expenses for equip- 

 ping the king's ship, The George, in the year 1345, that sixteen hour- 

 glasses had been bought in Flanders. This statement, however, is 

 by no means a proof of the use of the log. The ampolletas (or hour- 

 glasses) of the Spaniards were, as we most plainly find from the 

 statements of Enciso in Cespides, in use long before the introduc- 

 tion of the log, " echando punto por fantasia in la corredera de los 

 perezosos." 



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