January i8, 1889.] 



SCIENCE. 



45 



tor, for South America in the torrid zone has long been known. 

 There the explorer easily penetrates its recesses on its great rivers, 

 — the Orinoco, Amazon, and La Plata, — for they are navigable 

 from the ocean far into the interior. The Amazon, 3,000 miles 

 from its mouth, is only 210 feet above the ocean-level, and, with its 

 branches, is navigable for 10,000 miles. Africa also has three great 

 rivers, — one on each side of this peninsula. On the north, the 

 Nile, the river of the past, empties into the Mediterranean Sea, but 

 its navigation is soon interrupted by five cataracts ; so that the 

 camel, the ship of the desert, bears the wares of Europe from the 

 foot of the first cataract far up the river, 800 miles, to Berber, whence 

 they are again shipped by boat 2,000 miles to Gondokoro, close to 

 the lakes Albert and Victoria Nyanza, 4,000 feet above the sea-level, 

 4,200 miles by water from the Mediterranean. 



On the west, the Kongo, the river of the future, empties into the 

 Atlantic Ocean under the equatorial sun ; but its navigation is also 

 impeded by successive falls extending from its mouth to Stanley 

 Pool. Then there is almost uninterrupted navigation on the river 

 and its tributaries for 10,000 miles. Far inland the head waters of 

 its north-eastern branches interlace with the waters of the Nile. 

 Another branch rises in Lake Tanganyika in eastern Africa, 

 while the main river finds its source higher up in the mountains, 

 north of Lake Nyassa, 5,000 feet above the sea-level. On the east 

 the Zambezi, the great river of southern Africa, empties into the 

 Indian Ocean opposite Madagascar. The navigation of its main 

 branch, the Shire, is interrupted not far from the ocean. The 

 Zambezi itself is navigable to the rapids near Tete, 260 miles from 

 its mouth ; while one or two hundred miles higher up are , the 

 mighty falls of Victoria, only exceeded in volume of water by the 

 Niagara, and nearly equal in height. 



In whatever direction Europeans attempted to penetrate Africa, 

 they were met by insurmountable obstacles. Communication by wa- 

 ter was prevented by falls near the mouths of great rivers. The greater 

 part of the coast was most unhealthy, and, where not unhealthy, a 

 desert was behind it ; but these obstacles, which formerly pre- 

 vented exploration, now stimulate the traveller to explore the dark 

 continent. The modern explorations of Africa commenced one hun- 

 dred years ago, when Mungo Park crossed the Desert of Sahara, 

 and lost his Ufe in descending the Niger. From that time to the 

 present, travellers in ever-increasing numbers, entering Africa from 

 every side, have undertaken its exploration. Some who have entered 

 from the Atlantic or Pacific coasts have been lost in its wilds, and 

 nothing heard of them for one, two, or three years, when they have 

 emerged on the opposite coast ; others have passed from the coast, 

 and have never been heard from, stricken down by disease, or killed 

 by the natives. Zanzibar has been a favorite starting-point for the 

 lake region of Central Africa. Stanley started from Zanzibar on 

 his search for Livingstone with two white men, but returned alone. 

 Cameron set out by the same path with two companions, but, upon 

 reaching the lake region, he was alone. Keith Johnson, two or 

 three years ago, started with two Europeans : within a couple of 

 months he was gone. Probably every second man, stricken down 

 by fever or accident, has left his bones to bleach along the road. 

 Drummond, a recent explorer of Africa, chose a route by the Zam- 

 bezi and Shire Rivers as healthier and more desirable. Let us hear 

 his experience. Early in his journey, at the missionary station of 

 Livingstonia, on Lake Nyanza, he entered a missionary home : it 

 was spotlessly clean ; English furniture in the room, books lymg 

 about, dishes in the cupboards; but no missionary. He went to 

 the next house : it was the school ; the benches and books were 

 there, but neither scholars nor teacher. Next, to the blacksmith 

 shop : there were the tools and anvil, but no blacksmith. And so 

 on to the next and the next, all in perfect order, but all empty. A 

 little way off, among the mimosa groves, under a huge granite 

 mountain, were graves : there were the missionaries. 



The Niger is the only river in all Africa navigable any consider- 

 able distance above its mouth, by small steamers adapted to its 

 navigation ; but the Niger does not give access to the interior, as it 

 rises within 100 miles of the ocean, and, after making a great bend 

 around the mountains of the Guinea coast, empties into the ocean 

 only about five degrees south of its source, after a course of 2,500 

 miles. Its main branch, the Benue (or " Mother of Waters "), is 

 navigable 500 or 600 miles above its junction with the Niger. The 



country through which it flows is thickly peopled and well culti- 

 vated ; but the natives are fierce and warlike, and have until re- 

 cently prevented any exploration of the Benue. 



The Mountains of Africa. 



As mountain-ranges determine the course of rivers, influence the 

 rainfall, and temper the climate, we must understand the moun- 

 tain system of Africa before we can understand the continent as a 

 whole. 



From the Red Sea to the Cape of Good Hope, successive ranges 

 of mountains follow the coast, sometimes near, at others two or 

 three hundred miles inland ; the land, in the latter case, rapidly 

 ascending from the coast. The only breaks in this long chain are 

 where the Zambezi and Limpopo force their way to the Indian 

 Ocean. High peaks are found all along these ranges. 



In Abyssinia, on the Red Sea, there is a range of snow moun- 

 tains 14,700 feet in height. A few hundred miles to the south-east, 

 and near Lake Victoria Nyanza, is Kilima Ndjaro, 18,700 feet high, 

 — the highest mountain in Africa, — and the mountains of Massai- 

 Land, a continuation of the Abyssinian Mountains. Another 

 range, apparently an offshoot of the long range from the Red Sea, 

 forms a wall 100 miles long, and 10,000 feet high, on the east of 

 Lake Nyassa, separating the waters of the lake from the Indian 

 Ocean. This range continues to the Zambezi. South of this river 

 the mountains rise 8,000 to 10,000 feet in height. In Cape Colony 

 are several ranges of mountains. The highest peak is Compas 

 Berg, 8,500 feet. West of these ranges, in Ihe equatorial region, is 

 an elevated plateau in which is the lake region, then other ranges, 

 and a gradual descent towards the Atlantic. There are no con- 

 tinuous ranges of mountains on the western coast ; but at Kamerun 

 there is a cluster of mountains reaching an elevation of 13,100 feet ; 

 and south of Morocco some of the peaks of the Atlas Mountains reach 

 an elevation of 1 2,000 to 1 3,000 feet, but they have little if any influence 

 on the rainfall or temperature of the country. It will be seen from 

 this statement that in eastern Africa are high mountain-ranges and 

 an elevated plateau ; that the land in equatorial Africa gradually 

 descends toward the west and north-west until within one or two- 

 hundred miles of the Atlantic Ocean, when the descent is rapid to 

 the low and unhealthy coast-lands. North of Cape Colony, in the 

 territory claimed by Portugal, the general elevation of the interior 

 is 3,000 feet or over, sloping towards the valley of the Kongo near 

 the equator, then north of the Kongo rising to an elevation of about 

 2,000 feet, and descending to 1,200 feet at Lake Chad. 



Careful computations have been made to ascertain the average 

 elevation of the continent. The mean of the most careful estimates 

 is a little over 2,000 feet. The interior is therefore elevated above 

 the miasmatic influences of the coast, but exactly what effect this 

 elevation has upon the temperature can only be ascertained after 

 careful investigation and a series of observations. North of Guinea 

 and Senegambia the coast is less unhealthy ; but, as the Desert of 

 Sahara extends to the ocean, the country is of little value, and is 

 therefore left to the native tribes, unclaimed by Europeans. 



In the International Scientific Series it is stated that there are in 

 Africa about ten active volcanoes, — four on the west coast, and 

 six on the east, — but I have not found any corroboration of this 

 report, and think it very doubtful if there are any volcanoes now in 

 operation. The Kilirna Ndjaro and Kamerun were formerly active 

 volcanoes, for the craters still exist. In the south the diamond- 

 fields are of volcanic ash formation. 



The lake region of Africa stretches from the waters of the Nile 

 three degrees southward, to the waters of the Zambezi, fifteen de- 

 grees south, — a lake region unequalled, in extent and volume of 

 water, except by our lakes. Here is the Victoria Nyanza, the 

 queen of inland seas, 4,000 feet above the sea-level ; and a long 

 series of lakes, great and small, at equal elevation. The more 

 striking are Bangweolo to the south-west, the grave of Living- 

 stone, and Nyassa on the south-east. In their depths the Nile, 

 the Kongo River, and the Shire (the main branch of the Zambezi) 

 have their source. 



The great belt of equatorial Africa, situated between the I5tb 

 parallel of north latitude and the 1 5th parallel of south latitude, 

 has continuous rains, is everywhere well watered, and has a 

 rich and fertile soil. Some portions are thickly populated, and 



