The oasis of El-Kantara is the first we encounter on quitting the Mediterranean region to penetrate into the Sahara through the gloomy and precipitous ravine entitled "The Mouth of the Desert." It is situated 1800 feet above the sea-level. Its length is 5000 yards. Fournel, the first geologist who examined it (in 1864), christened it the Hyères of the Sahara. Its temperature is cool and equable, and does but just suffice to enable the dates to ripen. It possesses upwards of 76,000 palm-trees, sheltering under their leafy shadow legions of apricots, pomegranates, and fig-trees. In the centre of this pleasant and fruitful shade houses of brick, with flat roofs and narrow loop-holed windows, surround a square tower. The ancient watch-towers have fallen into decay. Before France took under its "protection" the peaceful Berbers who cultivate the oasis, these towers were useful as posts of observation whence to descry the approach of the wandering Arabs, who resort in summer to the pastures of the mountains, and in winter to those of the Sahara. * * * * * As a type of the oasis of the Desert of Erosion, let us take that of Ouargla, the last which submitted to the French in South Algeria. [Illustration: A Street in Ouargla.] It is situated in a profound hollow. In form it is elliptical, with its major axis measuring about five thousand yards, and its minor about three thousand. The palms are planted at the rate of ten to eleven hundred a hectare (two acres); they attain to extraordinary dimensions, and their dense foliage over-arches a small world of fruit trees. Outside the gardens grow some wild date-palms, which yield a smaller crop, but whose fruit is much more savoury. Two avenues, or clearings, bisecting the forest from north to south, lead to the _q'sour_, or village, of Ouargla. This _q'sour_, like every other, is built of sun-dried earth, and surrounded by a circular rampart in very bad condition, six to thirteen feet in height, and four and a-half feet thick at the base. It is flanked with loop-holed towers, and encircled externally by a muddy moat, crossed by six causeways leading to as many gates. Before some of these gates are planted the small entrenched camps, wherein the Arab shepherds of the neighbourhood take refuge with their flocks what time the oasis is menaced by an enemy.