BIVEBS OF MAROCCX). 869 regular trade route to be established along the cournc of the river, which neverthe- less waters one of the most pnxluctive regions in Marocco. The main stream torms the natural highway of communication between the Atlantic seaboard and the Moluya, draining to the Mt'diterrancan, and in the fertile plains watered by the Sebu is situated Fez, the first city in the empire. Travellers following the coast route from Tangier to Mogador cross the Sebu by a ferryboat of primitive structure, which does not relieve them from the necessity of wading through the mud. The tides ascend a long way up the lower course of the Sebu. About 18 miles south-west of the Sebu, the Bu-Uegrag reaches the Atlantic through a rocky channel excavated in the slightly elevated {)lateau. This river rises, not in the Great Atlas, like the Moluya, Sebu, and Draa, but in the advanced hills skirting the Fez territory on the south ; and although scarcely more than 120 miles long, it takes the foremost position in the political geography of the country; for it forms the frontier line between the two kingdoms of Fez and Marocco, and near it stood the outpost of Ad Mercuries, which marked the utmost limit of the Roman province of Mauritania Tingitana. The Ura-er-Rbia, or " Mother of Pastures," so named from the rich grazing- grounds skirting its banks, is said by Renu and Hooker to be the most copious stream in Marocco. During the dry season it is fordable at many points ; but in the rainy season travellers are detained for weeks on its bank, waiting the subsi- dence of the floods to cross over. For a space of about 120 miles, between the mouth of the Um-er-Rbia and the Tensift, no other watercourse reaches the sea. Not is the "Wed Tensift itself one of the great rivers of Marocco, although the city of Marocco lies in its basin. Hero the rainfall is far less abundant than in the northern provinces, and in summer the mouth of the Tensift is completely closed by the sands at low water. The Wed Sfts, the Subus of the ancients, which takes its rise between the Atlas and Anti-Atlas, is also an intermittent stream, flooded in winter, and throughout its lower course almost completely dry in sunmier. "When crossed by Lenz in March, below Tarudant, some 60 miles above its mouth, it was p mere rivulet 10 or 12 feet wide and less than 2 feet deep. The "Wed Assaka, which skirts the southern foot of the Atlas, is also mostly drj-, explorers often finding nothing but sand in its bed. Even the "Wed Draa, by far the longest river in Marocco, is much inferior in volume to the Moluya, Sebu, and Um-er-Rbia, and seldom reaches the Atlantic. Its chief headstreams rise in the snowy cirques of the Great Atla.s, and for a distance of about 180 miles, from the Idraren Deren to the A Yashin range, all the streams on the southern slope of the main range flow towards the Draa, which escapes southwards through a series of gorges in the Jebel Shagherun. For a space of 600 miles below the gorges its volume constantly diminishes, absorbed partly by the arable lands along its banks, partly by evajioration and infiltration in the sands. After emerging from the upj)er gorges, it flows at first southwards, skirted on both banks by a strip of palm groves, varying in breadth from 500 yards to nearly 2 miles. But after skirting the easteni extremity of the Bani range and
