OCEANIC DISCOVERIES. 255 



The early voyages of the Catalans to the north coast of Scot 

 land and the western shores of tropical Africa (Don Jayme 

 Ferrer reaching the mouth of the Rio de Ouro, in the month 

 of August, 1367), and the discovery of the Azores (the Bracir 

 Islands, on the Atlas of Picigano, 1367) by the Northmen, 

 remind us that the open Western Ocean was navigated long 

 before the time of Columbus. The voyages prosecuted under 

 the Roman dominion in the Indian Ocean, between Ocelis and 

 the coasts of Malabar, in reliance on the regularity of the di- 

 rection of the winds,* were now conducted by the guidance of 

 the magnetic needle. 



The application of astronomy to navigation was prepared 

 by the influence exercised in Italy, from the thirteenth to the 

 fifteenth centuries, by Andalone del Nero and John Bianchini, 

 the corrector of the Alphonsine tables, and in Germany by 

 Nicolaus de Cusa,t George von Peuerbach, and Regiomon- 

 tanus. Astrolabes designed for the determination of time and 

 of geographical latitudes by meridian altitudes, and capable of 

 being employed at sea, underwent gradual improvement from 

 the time that the astrolabium of the Majorcan pilots was in 

 use, which is described by Raymond Lully,$ in 1295, in his 

 Arte de Navegar, till the invention of the instrument made 

 by Martin Behaim in 1484 at Lisbon, and which was, per- 

 haps, oidy a simplification of the meteoroscope of his friend 

 Regiomontanus. When the Infante Henry, duke of Viseo, 

 who was himself a navigator, established an academy for pi- 

 lots at Sagres, Maestro Jayme, of Majorca, was named its di- 

 rector. Martin Behaim received a charge from King John 

 II. of Portugal to compute tables for the sun's declination, 

 and to teach pilots to " navigate by the altitudes of the sun 



azar, Discurso sobre los Progresos de la Hydrografia en Espana, 1809, 

 p. 7. * See ante, p. 172. 



t Regarding Cusa (Nicolaus of Cuss, properly of Cues, on the Moselle), 

 see ante, p. 109, and also Clemens's treatise, Ueber Giordano Bruno und 

 Nicolaus de Cusa, s. 97, where there is given an important fragment, 

 written by Cusa's own hand, and discovered only three years since, re- 

 specting a three-fold movement of the earth. (Compare, also, Chasles, 

 Aperqu sur I 'Origine des MHhodes en GSomStrie, 1807, p. 529.) 



t Navarrete, Dissertacion Hislorica sobre la parte que tuvieron los Es- 

 paiioles en las Guerras de Ultramar 6 de las Cruzadas, 1816, p. 100 ; and 

 Examen Crit., t. i., p. 274-277. An important improvement in observ- 

 ation, by the use of the plummet, has been ascribed to George von 

 Peuerbach, the instructor of Regiomontanus. The plummet had, how- 

 ever, long been employed by the Arabs, as we learn from Abul-Hassan- 

 Ali's description of astronomical instruments written in the thirteenth 

 century. Sedillot, Traite" des Instrumens Aslronomiques des Arabes, 183.5, 

 p. 379; 1841, p. 205. 



