SLEEP AND AWAKENING 17 
This change was one of the most remarkable of the 
whole renaissance. The Turk burnt the Alexandrine 
library and the Pope admitted the sphericity of the Earth ; 
the sceptre of intellect passed by these acts from Islam to 
Christendom, and the way was reopened to attack the 
problem of the Antarctic. The shifting of the balance 
of power began to press heavily on trade. The routes to 
the Far East were blocked by the Turk; but the products 
of the Far East had become indispensable to Europe. 
The possibility of a sea-passage to India became a press- 
ing affair, and Ptolemy’s Terra Incognita uniting the 
south of Africa with the Malay peninsula would bar the 
way; but here it appears that the early European geog- 
raphers were not altogether inclined to follow Ptolemy, 
and many even of the wheel-maps show the Indian Ocean 
open to the south. 
The problem of the sea-route to the East absorbed the 
attention of the Portuguese Prince Henry, of English de- 
scent on his mother’s side, whose life-long efforts to pro- 
mote maritime enterprise gained for him the surname of 
The Navigator. With the advent of Prince Plenry we 
pass from speculation to exploration, and thanks to his 
vigorous initiative the clouds of ignorance which had 
obscured three-quarters of the Earth’s surface for mil- 
lenniums, began to roll away. 
It is scarcely possible in the twentieth century for us 
to understand the horror of the unknown ocean which 
haunted the seafarers of the Mediterranean even so late 
as the beginning of the fifteenth century. It would seem 
as if the fancies of the ancient Greeks had expanded in 
vagueness and terror during the intellectual sleep until 
they became veritable nightmares. West of the Pillars 
of Hercules the portals of the pleasant Mediterranean, 
