[s. B. DAWSON] THE LINES OF DEMARCATION 515 



resulted in an estimation of 56 -I3 miles to a degi'ee and were accepted 

 as true by Friar Bacon and Cardinal D'Ailly and others of the favourite 

 authors of Colrnnbus, who, dividing that figure by four, arrived at the 

 conclusion he adhered to all his life that the length of a degree was 

 14 ^le leagues, and he even asserted that he had verified it on one of his 

 voyages to Guinea. It has not been absolutely proved that these Ara- 

 bian miles were equivalent to Roman miles ; but the inquiry is long 

 and it is sufficient now to say that they were taken to be equivalent, 

 and in the belief tliat the earth was much smaller than it is, the ad- 

 miral discovered America and thought it was India. In that way arose 

 the belief, to which the admiral and his son adhered, in a degree of 14 ^| g 

 leagues. 



The different estimations of the length of a degree at the close of 

 the fifteenth century can nearly all be traced back to some manipulation 

 of Ptolemy's figures. If his 500 stades be divided by eight — the true 

 divisor — we have another estimate often met with, viz., 62 ^jo miles to 

 a degree or 15 ^|s leagues. This again, in current writing was rounded 

 ofi^ to 60 miles and 15 leagues and given out al^o as Ptolemy's measure- 

 ment. Jaime Ferrer alone followed Eratosthenes and valued the de- 

 gree at 700 stades and, dividing by eight, he made it 87^1, miles ; this 

 divided again by four made 21 '^jg leagues in reality, though by some 

 error it is 21 °js in his opinion (App. D); but even he could not throw 

 off the influence of Ptolemy and as pointed out already was driven to 

 suppose that Ptolemy's 500 stades were longer and were equivalent to 

 the 700 of Eratosthenes. There was in fact no settled estimate and we 

 find in the opinion of Duran, Cabot and Vespucci, at Badajoz, that they 

 quote Ptolemy for a* length of 62 ^[2 miles while themselves valuing a 

 degree at 70 miles. 



It is an anachronism to expect, in the writers of pre-scientific days, 

 that precision of statement demanded by modem science and the reader 

 must be prepared to meet with occasional passages which conflict with 

 the general trend of the authorities. It is certain that Gromara held 

 to the valuation of 17 ^|o leagues ; but he also quotes Ptolemy loosely, 

 for he says (in Eden's translation) "He (Ptolemy) assigned likewise to 

 " every degree three score miles which make seventeen Spanish leagues 

 " and a half." Here are two manifest slips, because Ptolemy's degree 

 was 62 ^la miles and 17 ^[2 leagues were 70 miles. This last valuation 

 is beyond question ; for Fernan Columbus, in his official opinion at 

 Badajoz, says expressly that "Castillian or marine leagues" are four 

 miles in length. Again in a passage in the Fifth Decade of Peter 

 Martyr we find that author complaining that sailors counted the 175 

 leagues, from Borneo to Malacca as ten degrees, whereas "the ancient 



Sec. II., 1899. 33. 



