316 ROYAL SOCIETY OF CANADA 



"philosophers reckoned 15 leagues or GO miles to a degree." This 

 pass.ago shows how loosely l*toleiny wus quoted, and also that the belief 

 in IT ''.. Iwigues to a degree had then been established at sea. 



That which had been hidden from the learned throughout the 

 ages, was revealed to the pr-ictical mariner unskilled in book lore ; but 

 skilled to watch the elevation or sinking of the pole-star on a' northern or 

 southern course, and skilled also to estimate the dead reckoning of his 

 little vessel by the aid of his sand glass. Therefore, when the length 

 of voyages extended over thousands of miles, the elaborate measure- 

 ments of the Greeks and Arabians were found to be wrong and the 

 valuation of 17 ^|, leagues or 70 miles was accepted by sailors in ad- 

 vance of scholars. It was not far out of the way; since 70 Italian miles 

 are equal to 64-3 English statute miles and ()9-l of these hist miles are 

 now reckoned to be the length of a degree of a great circle. 



We may then conclude, with Navarrete and D'Avezac, that, at 

 least as early as A.D. loi 7, the valuation of 17 ^|o leagues had come into 

 general use. Humboldt unhesitatingly quotes the leagues of Torde- 

 sillas at that rate. Herrera w'ould seem to know. of no other ; for at 

 the very outset of his Hiatory, he gives the circumference of the earth 

 as 6,300 leagues. Magellan, writing in A.D. 1519, to King Ferdinand, 

 stated that the island of San Antonio is 23° east of the line of demar- 

 cation. He gave the latitude at 17°, proving that he was reckoning at 

 the rate of 17 ^|o leagues to an equatorial degree. At the convention 

 of Badajoz, in A.D. 1584, Rny de Villegas stated that he had measured 

 a degree with that result, and Thomas Duran, Sebastian Cabot and 

 Juan Vespucci, not only concurred in that valuation, but added that it 

 was the usual estimate of Spanish and Portuguese sailors. AVhile this 

 was the opinion of the Spanish pilots and experts, the Spanish judges 

 clung to the 62 ^l^ miles of Ptolemy ; because they thought that the 

 Portuguese were stretching out the distance to 70 miles for the pur- 

 pose of including the Spice Islands within their line. 



In A.D. 1529, at the treaty of Saragossa, the ratio of 17 \ leagues 

 v/as admitted on both sides ; for the Spaniards had recognized the fact 

 that, as each party had 180 degrees, the length of a degree made no 

 difference. It had to count on both sides, and in after years, whenever 

 the treaty came up for discussion the same ratio was made the basis of 

 argument. It persists all through the nautical authorities, not only in 

 Spain, but in Fi*ance ; for we find that Champlain, in A.D. 1632, when 

 giving instructions for making charts, laid down the rule that the scale 

 must be 17 ^|. leagues to a degree. 



The reader will see, from these remarks, tiiat the old writers deal 

 with only one league, that which was a multiple of the Roman mile. 



