CHAP. V I . ]
CHRISTOPHER
63
COLUMBUS.
parts of the East, made him extremely anxious that the splendid project of Prince Henry should be realized, and the Portuguese flag penetrate to the Indian seas. Impatient of the slowness with which his discoveries advanced along the coast of Africa, and of the impediments which every cape and promontory presented to nautical enterprise, he called in the aid of science to devise some means by which greater scope and certainty might be given to navigation.
His two physicians, Roderigo and Joseph, the latter
a Jew, the most able astronomers and cosmographers of his king dom, together with the celebrated Martin Behem, entered into a learned consultation on the subject.
The result of their confer
ences and labors was the application of the astrolabe to naviga tion, enabling the seaman, by the altitude of the sun, to ascertain his distance from the equator.*
This instrument has since been
improved and modified into the modern quadrant, of which, even at its first introduction, it possessed all the essential advantages. It is impossible to describe the effect produced upon naviga tion by this invention.
It cast it loose at once from its long
bondage to the land, and set it free to rove the deep.
The mari
ner now, instead of coasting the shores like the ancient navigators, and, if driven from the land, groping his way back in doubt and apprehension by the uncertain guidance of the stars, might adven ture boldly into unknown seas, confident of being able to trace his course by means of the compass and the astrolabe. It was shortly after this event, which had prepared guides for discovery across the trackless ocean, that Columbus made the first attempt, of which we have any clear and indisputable record, to procure royal patronage for his enterprise.
The court of Portu
gal had shown extraordinary liberality in rewarding nautical dis* Barros, decad. 1, lib. iv. cap. 2.
Maffei, lib. vi. p. 6 and 7.