In many respects the country lying to the north of the Atlas belongs, as Mr. L. March Phillips has pointed out,[4] more to the European than to the African system. It is distinctly European in aspect, in its variety of hills and valleys and rivers; it is European in its fertility, in its olive-groves and vineyards, its waving fields of grain, its forests of oak and pine; and it is European in climate, in the temperateness of its heat, which is no greater than that of southern Italy, and in the comparative abundance of its rainfall. The mighty barrier of the Great Atlas cuts it off completely from the Sahara, on which it seems to turn its back, while it faces the Mediterranean and the company of northern nations to which it feels related. Only when you have crossed the Atlas, when the verdure-clothed mountains and pleasant valleys give way to naked plains of sand, the pine-forests to occasional palm-groves, the houses of brick and stone to mud hovels and goat’s-hair tents, the settled agricultural population to nomadic sheep and camel-raisers, the light skins of the Berbers to the black ones of the negroes and the brown ones of the Arabs, do you fully realize that you are in Africa. And when, conversely, you turn your back upon the desert and emerge from the narrow defile of El Kantara upon the Algerian table-lands, you have the feeling that you are back in Europe again. * * * * * On leaving Biskra we headed straight north across the desert for El Kantara, forty miles away. Here the lofty wall of the Aurés is riven by a deep and narrow gorge, just wide enough to let the road, the railway, and the little rushing river through. It is called by the Arabs Foum-es-Sahara, the Mouth of the Sahara; but to us, coming up from the south, it was the gateway to the Tell. At the southern entrance to the gorge is the little oasis of El Kantara, which derives its name from a Roman bridge, much restored by the third Napoleon, for this was the site of Calcius Herculis, a fortress-town on Rome’s African frontier. Nestling amid the palm-groves of the oasis, or perched on the crags which mark the entrance to the pass, are three small villages, the Red, the Black, and the White, so named by the imaginative Arabs from the color of the bricks with which they are built, or, to be more exact, from the respective shades which they assume at sunrise and sunset.