Artesian Wells, so called from the French province of Artois, where they appear to have been first used on an extensive scale, are perpendicular borings into the ground through which water rises to the surface of the soil, producing a constant flow or stream, the ultimate sources of supply being higher than the mouth of the boring, and the water thus rising by the well-known law. They are generally sunk in valley plains and districts where the lower pervious strata are bent into basin-shaped curves.
The rain falling on the outcrops of these saturates the whole porous bed, so that when the bore reaches it the water by hydraulic pressure rushes up towards the level of the highest portion of the strata. The supply is sometimes so abundant as to be used extensively as a moving power, and in arid regions for fertilizing the ground, to which purpose artesian springs have been applied from a very remote period. Thus many artesian wells have been sunk in the Algerian Sahara which have proved an immense boon to the district.
The water of most of these is potable, but a few are a little saline, though not to such an extent as to influence vegetation. The hollows in which London and Paris lie are both perforated in many places by borings of this nature. At London they were first sunk only to the sand B B, but latterly into the chalk c o. One of the most celebrated artesian wells is that of Crenelle near Paris, 1798 feet deep, completed in 1841, after eight years' work. Artesian wells are now common in many countries, and have been sunk to the depth of a mile or more. As the temperature of water from great depths is invariably higher than that at the surface, artesian wells have been made to supply warm water for heating manufactories, greenhouses, hospitals, fish-ponds, etc. Petroleumwells are generally of the same technical description. Artesian wells were later made with larger diameters than formerly, and altogether their construction was rendered much more easy after the industrial revolution. Research Artesian Wells
The ISO (International Standards Organisation) assigns a two character code to each country name. These codes are used by Internet 'whois' databases (these two character abbreviations are the whois country codes) and also other applications.
A hamada is a rocky area of desert which has been swept clean of sand, dust and the like by the wind. The term is most usually applied to areas of the Sahara desert. Research Hamada
The sirocco is the hot, dry and sometimes dusty southerly wind blowing from the Sahara; it is experienced in North Africa, Sicily and southern Italy. Research Sirocco
The African hunting dog is a small, wild member of the dog family, Canidae. The single species, Lycaon pictus, is found in Africa south and east of the Sahara and is also known as the African wild dog or Capehuntingdog. The black-skinned, long-legged body weighs up to 23 kg and is covered with short, sparse fur in a wide range of black, yellow, and white patterns. The ears are large and rounded. Each paw has only four toes. The animal lives and travels in packs numbering from a few to more than 50 individuals. They sometimes range widely in their search for food. The dogs exhibit complex social patterns; both parents care for the young, who learn much about hunting and game-trail patterns from the older dogs in the pack. A large pack of dogs can bring down large animals, such as lions and antelopes. After a gestation period of about 70 days, six to eight young are born to a litter. Research African Hunting Dog
The baboon is seven species of Old World monkey in the genus Papio that have evolved from tree-dwelling ancestors to become terrestrial, walking on all four limbs. Typical open-country monkeys, they are found all over the savannah, semi-desert, and lightly forested regions of Africa south of the Sahara Desert. (The species of baboons known as the mandrill and the drill, however, live in more forested habitats.) The face is elongated and rather dog-like, and the jaw carries a long row of grinding molar teeth.
Baboons feed on the ground, eating seeds, tubers, grass, insects, and small animals, and this makes them vulnerable to predators. Troops of baboons will often associate with a herd of ungulates such as impala, which are alert and will give warning of approaching predators. The association is of mutual benefit, as baboons are powerful animals and give protection to the impala from smaller predators. The hamadryas baboon, Papio hamadryas, is 76 centimetres tall with a tail 61 centimetres long; the females have brown hair and the males have grey hair with a long mane. They live in highly organized societies of twenty-five to thirty animals, and occasionally in groups of up to 200. The society is usually hierarchical, and the males defend females with young. A single offspring is born and it is carried by its mother for several months. Other species are the common, or savannah, baboon, Papio cynocephalus, and the gelada baboon, Theropithecus gelada. Research Baboon
The buffalo is several species of large wild cattle distinguished by their horns being flattened at the base and triangular in section. The typical African Buffalo (Synceros caffer) inhabits open bush country generally near rivers all over Africa south of the Sahara.
The common or Indian buffalo (Bubalus Buffelus or BosBubalus) is larger than the ox and with stouter limbs, originally from India, but now found in most of the warmer countries of the Eastern Continent. A full-grown male is a bold and powerful animal, quite a match for the tiger. The buffalo is less docile than the common ox, and is fond of marshy places and rivers. It is, however, used in tillage, draught, and carriage in India, Italy, etc. The female gives much more milk than the cow, and from the milk the ghee or clarified butter of India is made. The hide is exceedingly tough, and a valuable leather is prepared from it, but the flesh is not very highly esteemed.
Another Indian species is the arnee (Bubalus. ami), the largest of the ox family. The name buffalo is also applied to wild oxen in general, and particularly to the bison of North America. Research Buffalo
The giraffe (formerly known as the camelopard) is the tallest mammal, reaching a height of over four meters, and found only in Africa south of the Sahara. A member of the family Giraffidae, suborder Ruminantia of the order Artiodactyla, there are two distinct species of giraffe, the common or blotched giraffe (Giraffa camelopardalis) and the reticulated or Somali giraffe (Giraffa reticulata). The giraffe has a short body, but very long neck and legs. The head is furnished with short horns covered with skin and short tufts of hair. There may be one pair of horns or two pairs, one shorter pair behind the longer front horns, and often between the front pair a central swelling on the forehead which may be as long as the horns. The markings of a giraffe varies from each animal, being unique with no two giraffes identical. A group of giraffes is known as a 'tower'. Research Giraffe More pictures of Giraffe
The Hyena is an African carnivore, of the family Hyaenidae. It has a large head and neck, long, well-developed forelegs, and powerful jaws and premolars adapted for crushing bones. Each foot has four toes with non-retractable claws, well suited for running on the open plains where hyenas feed on hoofed animals. Of the three hyena species, the best known is the spotted, or laughing, hyena (Crocuta crocuta) , the only member of its genus. Ranging south of the Sahara, it is the largest and most robust of the hyenas, with a length of 1.8 m and a height of 90 centimetres at the shoulder. Adults are brown-grey with dark brown or black spots. Named for their cry, which has been compared to hysterical human laughter, they also emit a striking howl that rises in pitch. Spotted hyenas were long thought to be only scavengers (warring African tribes abandoned their dead to the animal). Recently, hyenas have been found to be among the chief predators of herbivores, especially zebra and wildebeest.
The hyenas attack in packs at night, ripping open the flanks of their prey and carrying off the carcasses. Hyenas associate in clans cantered around communal dens occupied by batches of young at varying stages of growth. Females conceive throughout the year, giving birth after 110 days to one or two cubs, which dig their own tunnels. Pair bonding is not evident; the female, larger than the male, selects her mating partners. The female sexual organs have an external resemblance to the male's, a phenomenon probably related to scent identification, which plays a large part when clan members encounter one another.
A clan may consist of ten or twelve females, twenty cubs, and a number of males on the fringe; hyenas are very territorial. Little is known about the genus Hyaena , which comprises the striped hyena, Hyaena Hyaena , and the brown hyena, Hyena brunnea. Both bear manes of coarse, erectile hair and are smaller and far less aggressive than the spotted hyena. The striped hyena, grey-tan with vertical stripes, ranges from East Africa north into Asia. It is largely a scavenger, often eating vulture-picked bones. The brown hyena, found in southern Africa, is dark brown with a grey head and striped legs. It feeds mainly on fish and crabs. Research Hyena
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Abbreviations
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