If we open our atlases and turn to the maps of Africa, America, Asia, and Australia, we shall find that in each continent there are blank spaces. Sometimes these are called deserts or forests, but often we can only guess at the character of the country from the fact of there being no rivers marked and very few names of towns and cities.
The most famous of all deserts is the Great Sahara, which extends for thousands of miles across the north of Africa. Most people picture it as a huge sandy plain, where there is no water and no sign of life or vegetation; but, in reality, although there are districts where the shifting sandhills stretch away as far as the eye can see, a vast part of the Sahara consists of a stony tableland covered with a scanty growth of low, thorny bushes.
In the deserts there are, moreover, many fertile spots looking like exquisite little green islands set in the midst of a glowing, yellow sea. They are called oases, and are found where there are wells or pools of water. Arabs live in these places, cultivating the land and building mud-houses, while other tribes spend their time in wandering about the desert, seeking food for their animals and trading in the scattered towns and villages. These wanderers, or nomads, with their camels, horses, and herds of sheep and goats, may be seen slowly moving across the great sunburnt plain and pitching their brown tents at night among the sand-dunes.
MIXED TRANSPORT IN NIGERIA.
The nomadic Arabs travel in large parties called caravans, for there are brigands in the Sahara who would rob and murder lonely wayfarers. The men in the caravan often ride, and their horses are considered the finest in the whole world. The Arabs prize these horses highly and treat them well, never allowing them to be teased by the children, and, at the end of a long day's journey, giving them their meal of milk and dates before they eat anything themselves.
Horses, however, are only used for riding, and all the hard work is done by the camels, "the ships of the desert," as they are called. It is a strange sight to see a great caravan crossing the desert, sometimes as many as a thousand camels marching along in single file, each with a heavy load on his back.
Camels are strange animals, for although they are strong and have wonderful powers of endurance, they are surly, intractable, and even more obstinate than mules. Occasionally a camel will consider that he is overloaded, and lying down will snarl at his driver and refuse to move. Blows and commands are useless in such a case, but if the driver pretends to remove something from the burden the animal is often completely deceived, and thinking that he has outwitted his master and gained a victory, will rise to his feet and start off contentedly on the journey.
One of the greatest dangers of desert travel is lack of water, for wells are very few and far apart. Camels are particularly suited to these conditions, as they can live for several days without drinking, and when no water is forthcoming, will plod patiently on and on, until their strength is exhausted and they fall down beneath their heavy loads.