from the Tugurt, Wargla, and Sûf oases, and Bambara, Haussa, and other Negroes from Sudan. An ethnographic survey of the upper town may thus be compared to a journey in the interior as far as Timbuktu.

Notwithstanding the lofty and somewhat imposing structures erected under the French administration, the most interesting monuments are undoubtedly those

Fig. 105. — Military lines of Algiers.

that date from the Mohammedan period. But of these but few have survived. Of the mosques, numbering over one hundred and sixty, not more than twenty now remain, including the graceful mosque of Abd-er-Rahman Et-Tsalbi, whose elegant minaret rises above the foliage of the Marengo gardens near the Bab-el--