Pastoralists and semipastoralists, the Imuha (Tuareg) clans in the West African desert and Sahel (semiarid pastureland) have since circa 1000 B.C.E. built, disassembled, and rebuilt their dwellings each time they have moved to different areas for food and forage. Their homes are made of a lashed framework of acacia covered with cloth and/or leather. Built with space acuity in mind (the efficient use of space in a dwelling or other building), the shelters must protect extended families from desert heat, wind, and sandstorms. Ibn Khaldun in Kitab al-'Ibar, wa-diwan al-mubtada' wa-'l-khabar fi ayyam al-'arab wa-'l-'ajam wa-'l-barbar (The Book of Examples and the Register of Subject and Predicate [or, of the Origin and History], on the Days of the Arabs, the Persians, and the Berbers, 1374-1378 C.E.) refers to the "veil-wearers" (the men cover their faces below the...