which all mediæval maps took. Roughly speaking, of course, there was a certain amount of truth in the statement, since Jerusalem would be about the centre of the world as known to the ancients—at least, measured from east to west; but, at the same time, the mediæval geographers adopted the old Homeric idea of the ocean surrounding the habitable world, though at times there was a tendency to keep more closely to the words of Scripture about the four corners of the earth. Still, as a rule, the orthodox conception of the world was that of a circle enclosing a sort of T square, the east being placed at the top, Jerusalem in the centre; the Mediterranean Sea naturally divided the lower half of the circle, while the Ægean and Red Seas were regarded as spreading out right and left perpendicularly, thus dividing the top part of the world, or Asia, from the lower part, divided equally between Europe on the left and Africa on the right. The size of the Mediterranean Sea, it will be seen, thus determined the dimensions of the three continents. One of the chief errors to which this led was to cut off the whole of the south of Africa, which rendered it seemingly a short voyage round that continent on the way to India. As we shall see, this error had important and favourable results on geographical discovery.
Another result of this conception of the world as a T within an O, was to expand Asia to an enormous extent; and as this was a part of the world which was less known to the monkish mapmakers of the Middle Ages, they were obliged to fill out their ignorance by their imagination. Hence they located in Asia all the legends which they had derived either from Biblical or classical
