Alongside of this system of the square was another equally curious--that of the egg. Its author was the famous Venerable Bede, one of the most enlightened men of his time, who was educated at the University of Armagh, which produced Alfred and Alcuin. He says: "The earth is an element placed in the middle of the world, as the yolk is in the middle of an egg; around it is the water, like the white surrounding the yolk; outside that is the air, like the membrane of the egg; and round all is the fire which closes it in as the shell does. The earth being thus in the centre receives every weight upon itself, and though by its nature it is cold and dry in its different parts, it acquires accidentally different qualities; for the portion which is exposed to the torrid action of the air is burnt by the sun, and is uninhabitable; its two extremities are too cold to be inhabited, but the portion that lies in the temperate region of the atmosphere is habitable. The ocean, which surrounds it by its waves as far as the horizon, divides it into two parts, the upper of which is inhabited by us, while the lower is inhabited by our antipodes; although not one of them can come to us, nor one of us to them." [Illustration: FIG. 42.--THE EARTH AS AN EGG.] This last sentence shows that however far he may have been from the truth, he did not, like so many of his contemporaries, stumble over the idea of up and down in the universe, and so consider the notion of antipodes absurd. [Illustration: FIG. 43.--THE EARTH AS A FLOATING EGG.] A great number of the maps of the world of the period followed this idea, and drew the world in the shape of an egg at rest. It was broached, however, in another form by Edrisi, an Arabian geographer of the eleventh century, who, with many others, considered the earth to be like an egg with one half plunged into the water. The regularity of the surface is only interrupted by valleys and mountains. He adopted the system of the ancients, who supposed that the torrid zone was uninhabited. According to him the known world only forms a single half of the egg, the greater part of the water belonging to the surrounding ocean, in the midst of which earth floats like an egg in a basin. Several artists and map-makers adopted this theory in the geographical representations, and so, whether in this way or the last, the egg has had the privilege of representing the form of the earth for nearly a thousand years.