292 rosMoa. 



time clcar]y distinguished from that by the determma ion d 

 ^he longitude, ^9or la altiira del Este-Oeste.^ 



The importance of determining the position of the papal 

 Ime of deniarkaiion, and of thus fixing the hmits between the 

 possessions of the Portuguese and Spanish crowns ni the new- 

 ly-discovered land of Brazil, and in the group of islands in the 

 South Indian Ocean, increased, as we have already observed, 

 the desire for ascertaining a practical method for determining 

 the longitude. Men perceived how rarely the ancient and im- 

 perfect method of lunar eclipses employed by Hipparchus could 

 be applied, and the use of lunar distances was recommended 

 as early as 1514 by the Nuremberg astronomer, Johann AVer* 

 ner, and soon afterward by Orontius Finaeus and Gemma 

 Frisius, Unfortunately, however, these methods also remain- 

 ed impracticable until, after many fruitless attempts with the 

 instruments of Peter Apianus (Bienewitz) and Alonso de San- 

 ta Cruz, tne mirror sextant was invented by the ingenuity of 

 Newton in 1700, and was brought into use among seamen by 

 Hadley in 1731. 



The influence of the Arabian astronomers acted, through 

 the Spaniards, on the general progress of nautical astronomy. 

 Many methods were certainly attempted for determining the 

 longitude, which did not succeed ; and the fault of the want 

 of success was less rarely ascribed to the incorrectness of the 

 observation, than to errors of printing in the astronomical 

 ephemerides of Regiomontanus which were then in use. The 

 Portuguese even suspected the correctness of the astronomical 

 data as given by the Spaniards, whose tables they accused of 

 being falsified from political grounds.! The suddenly-awak- 

 ened desire for the auxiliaries which nautical astronomy prom- 

 ised, at any rate theoretically, is moat vividly expressed in the 

 narrations of the travels of Columbus, Amerigo Vespucci, Piga- 

 fetta, and of Andreas de San Martin, the celebrated pilot of 

 the Magellanic expedition, who was in possession of the meth- 

 ods of Pvuy Falero for determining the longitude. Oppositions 

 of planets, occupations of the stars, differences of altitude be- 

 tween the moon and Jupiter, and changes in the moon's dec- 

 lination, were all tried with more or less success. We pos- 

 sess observations of conjunction by Columbus on the night of 

 the 13th of January, 1493, at Haiti. The necessity for at- 



* Navarrete, Coleccion de los Viages y Desciihrimicntos que Htci6ron 

 t>or mar los Espanoles, X. iv., p. xxxii. (in the Noticia Biografhica a, 

 fernando dc Magcllanes). 



i Ban-OS, ')ec. iii., parte ii., p. G50 and Go8-662. 



