CL'EAXIC DISCOVERIES. 277 



changed, the air became temperate, a^d the Veshiiess mcreas- 

 ed the further we advanced." 



This passage, which is elucidated by many others in the 

 writings of Cohimbus, contains views of physical geography, 

 observations on the influence of ffeofrrauhical lonofitude on the 

 declination of the magnetic needle, on the inflection of the iso- 

 thermal lines between the western shores of the Old and the 

 eastern shores of the New Continent, on the position of the 

 Great Saragossa bank in the basin of the Atlantic Ocean, and 

 on the relations existing between this part of the ocean and 

 the superimposed atmosphere. Erroneous observations made 

 in the vicinity of the Azores, on the movement of the polar 

 star,* had misled Columbus during his first voyage, from the 

 inaccuracy of his mathematical knowledge, to entertain a be- 

 lief in the irregularity of the spheroidal form of the earth. In 

 the western hemisphere, the earth, according to his views, " is 

 more sicollen, so that ships gradually arrive nearer the heav- 

 ens on reaching the line [raija), where the magnetic needle 

 points due north, and this elevation {cuesta) is the cause of 

 the cooler temperature." The solemn reception of the admi- 

 ral in Barcelona took place in April, 1493, and as er.rly as the 

 4th of May of the same year, the celebrated bull was signed 

 by Pope Alexander VI., which " establishes to all eternity" 

 the line of demarkationf between the Spanish and Portuguese 



* Ohsei-vations de Christophe Colomb sur le Passage de la Polaire par 

 le Meridien, iii my Relation Hist., t. i., p. 506, aud in the Er.amen Crit., 

 t. iii., p. 17-20, 44-51, and 56-61. (Compare, also, Navarrete, in Co- 

 lumbus^ s Journal of 16th to 30th of September, 1492, p. 9, 15, aud 254.) 



t On the singular differences of the " Bula de concesion ^ los Reyes 

 Catolicos de las Indias descubiertas y que se descubiereij" of May 3. 

 1493, and the " Bula de Alexandre VI., sobre la particion del oceano"' 

 of May 4, 1493 (elucidated in the Bula de estension of the 25th of Sep- 

 tember, 1493), see Examen Crit., t. iii., p. 52-54. Very different from 

 this line of demarkation is that settled in the " Capitulaciou de la par- 

 ticion del Mar Oceano entre los Reyes Catolicos y Don Juan, Rey de 

 Portugal," of the 7th of June, 1494, 370leagues (17i to au equatorial de- 

 gree) west of the Cape Verd Islands. (Compare Navarrete, Coleccion 

 de los Viages y Descub. de los Esp., t. ii., p. 28-35, 116-143, nnd 404 ; t. 

 iv., p. 55 and 252.) This last-named line, which led to the sale of the 

 Moluccas (de el Moluca) to Portugal, 1529, for the sum of 3^0,000 gold 

 ducats, did not stand in any connection wdtli magnetical or meteorolog 

 leal fancies. The papal lines of demarkation deserve, however, mora 

 careful consideration in the present work, because, as I have mention- 

 ed in the text, they exercised great influence on the endeavors to im- 

 prove nautical astronomy, and especially on the methods attempted for 

 the determination of the longitude. It is also very deserving of notice, 

 that the capitulacion of June 7, 1494, affords the first example of a pro- 

 posal for the establishment of a meridian in a permanent nv>Que" 1>T 



