tion there are no more human habitations, nothing being met except at long intervals the camping-grounds of the Tuareg nomads. Such are Inzize, Timissau and some other places, where a little water can be had.
The groups of oases, however, begin again east of the Twat district properly so called, beyond an intervening stony tract about 7 miles broad. Here are grouped the settlements of Tidikelt, Aulaf, Titt, and Akebli, the last-named noted throughout the whole of the Sahara as a market for black slaves, and as a general rendezvous for travellers and caravans proceeding southwards to the Sudan. In the neighbourhood are some alum mines, worked by the natives.
In this district the most important palm groves are those of Insalah (the Ain-Salah, or "Fountain of Peace" of the Arabs), which lie in the northern part of the Tidikelt oasis. Here several villages follow from north to south along the
margin of a sebkha at the foot of a range of sandhills, which skirts the east side of the saline. An underground channel tapped by wells, in which is collected the water oozing through the sands, yields a sufficient supply for the plantations. The area of cultivated land has even recently been greatly extended at the expense of the sebkha and of some unproductive thickets of shrubs.
In Twat, as in the rest of the Sahara, the land belongs to whoever sinks a well, keeps it in repair, and "quickens" the soil; But works of this sort can be undertaken only by the whole tribe acting in concert, or by the more powerful chiefs, who can employ forced or voluntary labour. In the Insalah oasis the system of great domains generally prevails, The sheikh and other members of his family own severally many thousands of palms, and surround themselves with hundreds of retainers, who eat their bread and champion their cause. In Twat, however, there
