"Does it not then seem a likely thing," said his Discretion, "that the sea is in the nature of a long low hill, down which the ships go?  So have I heard it surmised by wise men, sages and scholars of the lights of heaven, in the cities of Greece and Egypt.  For the earth and the ocean-sea, they teach, is fashioned as a vast globe in the heights of heaven.  And truly, if indeed it be the shadow of the world which darkens the face of the moon in time of eclipse, the earth may well be round, for that shadow is round.  Thus, then, one holding ever a westward course might sail down the bulge of the sea, and under the world, and round about even unto the east, if there be sea-way all along that course."