The Sahara Desert
The Sahara Desert - The World's Largest Desert
The world's largest desert, which takes up an area of more than one-quarter of Africa and stretches across the continent from the Atlantic to the Red Sea, is called the Sahara, which is the Arabic word for 'wilderness'. Except in the west, the desert borders the Mediterranean Sea and stretches south to within about 1,000 miles of the equator. Its surface is mostly divided by broad ridges into shallow basins. Rain falls but rarely, is scanty in amount and uncertain in its season. Day temperatures are often very high but the nights are cool and frost is not unknown. The sky is usually cloudless and the air very dry.
The Sahara is not just a great sandy plain. It has some quite high mountains and wide, bare tablelands (hammada). Sun and frost break up the rocky surfaces and the wind sorts out the fragments. The finest dust is carried away in great clouds. The sandy grains are blown into dunes which cover wide areas known as erg. In other parts (the reg) the whole surface is a mass of pebbles rounded and polished by the drifting sand.
The lack of water prevents the growth of vegetation and this limits the numbers of animals and men that can live in the desert. The plants protect themselves against loss of water by having few leaves (some have spines instead), thick skins and roots which go down deep. The animals are of kinds that can travel far and fast and live for some time without drinking. They include gazelles, antelopes, jackals and foxes. The most important tree is the date, whose fruit is eaten by the people and whose crushed seeds are used to feed the camels.
Several years ago the people of the Sahara belonged to one or other of two groups - the nomads or wanderers and the settled folk. The nomads bred camels, goats and sheep, moving from place to place so that the animals could graze on the scanty pasture. Milk and dates were the nomads main foods. The settled folk lived along the streams in the hilly country or where water could be obtained by digging wells — that is, the oases. The date palm provided them with food, timber and leaves for basket making. Fruit trees and vegetables were grown in the shade of the palms. Barley, wheat and tobacco were other crops. Iron, manganese and copper were found in places and oil (petroleum) was obtained at Hassi Messaoud and Edjele in eastern Algeria.
Transport across the Sahara Desert was very limited and once restricted to caravans which were formed by long lines of camels carrying foreign cloth and manufactured goods to the desert settlements in exchange for salt, dates and hair.