Читать книгу Stanley's Story; Or, Through the Wilds of Africa - A. G. Col. Feather - Страница 6

Table of Contents

The General Geological Formation of the Continent — The Want of Comprehensive Investigation — Singular Facts as to the Desert of Sahara — The Question of the Antiquity of Man — Is Africa the Birth-place of the Human Race? Opinions of Scientists Tending to Answer in the Affirmative — Darwinism.

It is to be greatly regretted that no comprehensive geological surveys of Africa have ever been made; because there are certain questions, eventually to be settled by geology, whose determination, it appears to be agreed, will be finally resolved by investigations in this continent. In a volume of this nature, designed for the general reader, those facts and reasonings only need be referred to which may be supposed to have the most interest. Reference has already been made to Sir Roderick Murchison’s exposition of the trough-shaped form of South Africa in his discourse before the Royal Geographical Society in 1852—an exposition which was so remarkably substantiated by Dr. Livingstone in his journey across the continent from Loanda to Kilimane. Though in its geographical configuration Africa is not greatly unlike South America, in its geological structure it much more resembles the northern continent of the western hemisphere. The Appalachian range of mountains extending through nearly the whole of the eastern portion of North America, parallel with the coast, and the Rocky Mountains and Sierra Nevadas in the west, bear a notable resemblance to those ranges of mountains in Africa, which, rising first in the northern portions of Senegambia, pursue a south-easterly, then a southerly course to near the southern limit of the continent, when they sharply bend toward the northeast, and with many lofty peaks, some of which reach the region of eternal snow, pass through Mozambique, Zanguebar, and end not until after they have passed through Abyssinia and Nubia, and penetrated the limits of Egypt. In Tripoli, Tunis, Algeria, and Morocco, is the Atlas range, between which and the beginning of the other the distance is hardly so great as that between the southern limits of the Appalachian range and the mountains of Mexico. The course of each of the great rivers of these continents is also across the degrees of latitude instead of generally parallel with the equator, as is the case with the great river of South America. There is a similarity also between North America and Africa in an extensive system of inland lakes of fresh water and vast extent.

ARAB CHIEF OF CENTRAL AFRICA.

The geological structure of the mountains of Africa, especially of South Africa, appears to be quite uniform. They have a nucleus of granite which often appears at the surface and forms the predominating rock, but in the greater proportion of the mountains, perhaps, the granite is overlain by vast masses of sandstone, easily distinguished by the numerous pebbles of quartz which are embedded in it. The summit, when composed of granite, is usually round and smooth, but when composed of the quartzose sandstone is often perfectly flat. Of this Table Mount, in South Africa, is a notable illustration. The thickness of this stratum of sandstone is sometimes not less than 2,000 feet. Such is the case in the Karoo mountains of Cape Colony. When thus appearing, it may be seen forming steep, mural faces, resembling masonry, or exhibiting a series of salient angles and indentations as sharp, regular, and well-defined as if they had been chiselled. With the granite are often associated primitive schists, the decomposition of which seems to have furnished the chief ingredients of the thin, barren clay which forms the characteristic covering of so much of the South African mountains. In some places, more recent formations appear, and limestone is seen piercing the surface. The geological constitution of the Atlas Mountains, in northwestern Africa, presents old limestone alternating with a schist, often passing to a well-characterized micaceous schist, or gneiss, the stratification of which is exceedingly irregular. Volcanic rocks have here been found in small quantities. There are veins of copper, iron, and lead.

In Egypt we find the alluvial soil a scarcely less interesting object of study than the rocks upon which it rests. These are limestone, sandstone, and granite, the latter of which, in Upper Egypt, often rises 1,000 feet above the level of the Nile. Not many years ago were discovered about 100 miles east of the Nile, and in 28 deg. 4 min. of north latitude the splendid ruins of the ancient Alabastropolis, which once derived wealth from its quarries of alabaster. Farther south are the ancient quarries of jasper, porphyry, and verd antique. The emerald mines of Zebarah lay near the Red Sea.

The Atlas range in Algeria is better known than elsewhere. It is as described above, but at Calle there are distinct traces of ancient volcanoes. Iron, copper, gypsum, and lead are found in considerable quantities. Cinnabar is found in small quantities. Salt and thermal springs abound in many parts of Algeria, amethysts in Morocco, slates in Senegambia, and iron in Liberia, Guinea, the Desert of Sahara and many other parts of Africa.

Gold, gold-dust, and iron are among the best known of the mineral riches of Africa, and are the most generally diffused throughout the continent. In the country of Bambouk, in Senegambia, most of the gold which finds its way to the west coast is found. Here the mines are open to all, and are worked by natives who live in villages. The richest gold mine of Bambouk, and the richest, it is believed, yet discovered in Africa, is that of Natakoo—an isolated hill, some 300 feet high and 3,000 feet in circumference, the soil of which contains gold in the shape of lumps, grains, and spangles, every cubic foot being loaded, it is said, with the precious metal. The auriferous earth is first met with about four feet from the surface, becoming more abundant with increase of depth. In searching for gold the natives have perforated the hill in all directions with pits some six feet in diameter and forty or fifty feet deep. At a depth of twenty feet from the surface lumps of pure gold of from two to ten grains weight are found. There are other mines in this portion of Africa, gold having been found distributed over a surface of 1,200 square miles. The precious metal is not only found in hills, the most of which are composed of soft argillaceous earth, but in the beds of rivers and smaller streams, so that the lines of Bishop Heber’s well-known missionary hymn are truthful as well as poetical:—

“Where Afric’s sunny fountains,

Roll down their golden sands.”

The gold mines of Semayla, which are some forty or fifty miles northward of those of Natakoo, though nearly as rich as the latter, are in hills of rock and sandstone, which substances are pounded in mortars that the gold may be extracted. Barth judged that gold would be found in the Benue river, the principal eastern tributary of the Niger. Gold, silver, iron, lead and sulphur have been found in large quantities, and were long profitably mined in the mountainous districts of Angola. In Upper Guinea gold and iron are deposited in granitic or schistose rocks. The interior contains vast quantities of iron which might be easily mined, but the natives are not sufficiently enterprising to accomplish much in this respect. Gold is also obtained in the beds of some of the rivers of Guinea. In Mozambique, on the east coast, the Portuguese have for a great length of time had a considerable commerce in gold obtained from mines near the Zambezi, in the region near the western limit of that province. It has already been stated that here Dr. Livingstone discovered deposits of coal. Along the Orange and Vaal rivers, in extreme South Africa, have recently been discovered diamond fields which some noted scientists believe will yet prove to be among the richest in the world.

ARRIVAL OF THE EXPEDITION ON THE BANKS OF THE ZAMBESI.

Perhaps the portions of Africa which are the most interesting on account of geological investigations which have been made, are the valley of the Nile in Egypt, and the Desert of Sahara. It is well known that the river Nile annually overflows its banks in Egypt, and the inundation remaining a considerable period, a thin layer of soil is each year added to that which existed there before. This Nile mud, as it is called by geologists, has been the subject of considerable scientific examination for many years. In his work upon the “Geological Evidences of the Antiquity of Man,” Sir Charles Lyell gives a full account of certain systematic borings in the Nile mud which were made between the years 1851 and 1854, under the superintendency of Mr. Leonard Horner, but who employed to practically conduct the examinations an intelligent, enterprising, and faithful Armenian officer of engineers, Hekekyan Bey, who had for many years pursued scientific studies in England, was in every way qualified for the task, and, unlike Europeans, was able to endure the climate during the hot months, when the waters of the Nile flow within their banks. Sir Charles Lyell states that the results of chief importance arising out of this inquiry were obtained from two sets of shafts and borings—sunk at intervals in lines crossing the great valley from east to west. One of these consisted of fifty-one pits and artesian perforations made where the valley is sixteen miles wide between the Arabian and the Libyan deserts, in the latitude of Heliopolis, about eight miles above the apex of the delta. The other line of pits and borings, twenty seven in number, was in the parallel of Memphis where the valley is five miles wide. Besides Hekekyan Bey, several engineers and some sixty workmen, inured to the climate, were employed for several years, during the dry season, in the furtherance of these interesting investigations.

It was found that in all the works the sediment passed through was similar in composition to the ordinary Nile mud of the present day, except near the margin of the valley, where thin layers of quartzose sand, such as is sometimes blown from the adjacent desert by violent winds, were observed to alternate with the loam. A remarkable absence of lamination and stratification, the geologist goes on to say, was observed almost universally in the sediment brought up from all points except where the sandy layers above alluded to occurred, the mud closely agreeing in character with the ancient loam of the Rhine. Mr. Horner attributes this want of all indication of successive deposition to the extreme thinness of the film of matter which is thrown down annually on the great alluvial plain during the season of inundation. The tenuity of this layer must indeed be extreme, if the French engineers are tolerably correct in their estimate of the amount of sediment formed in a century, which they suppose not to exceed on the average five inches. It is stated, in other words, that the increase is not more than the twentieth part of an inch each year, or one foot in the period of 240 years. All the remains of organic bodies found during these investigations under Hekekyan Bey belonged to living species. Bones of the ox, hog, dog, dromedary, and ass were not uncommon, but no vestiges of extinct mammalia were found, and no marine shells were anywhere detected. These excavations were on a large scale, in some instances for the first sixteen or twenty-four feet. In these pits, jars, vases, and a small human figure in burnt clay, a copper knife, and other entire articles were dug up; but when water soaking through from the Nile was reached, the boring instrument used was too small to allow of more than fragments of works of art being brought up. Pieces of burnt brick and pottery were constantly being extracted, and from all depths, even where they sank sixty feet below the surface toward the central parts of the valley. In none of these cases did they get to the bottom of the alluvial soil. If it be assumed that the sediment of the valley has increased at the rate of six inches a century, bricks at the depth of sixty feet have been buried 12,000 years. If the increase has been five inches a century, they have lain there during a period of 14,400 years. Lyell states further on that M. Rosiere, in the great French work on Egypt has estimated the rate of deposit of sediment in the delta at two inches and three lines in a century. A fragment of red brick has been excavated a short distance from the apex of the delta at a depth of seventy-two feet. At a rate of deposit of two and a-half inches a century, a work of art seventy-two feet deep must have been buried more than 30,000 years ago. Lyell frankly states, however, that if the boring was made where an arm of the river had been silted up at a time when the apex of the delta was somewhat further south, or more distant from the sea than now, the brick in question might be comparatively very modern. It is agreed by the best geologists that the age of the Nile mud cannot be accurately, but only approximately calculated by the data thus far furnished. The amount of matter thrown down by the waters in different parts of the plain varies so much that to strike an average with any approach to accuracy must be most difficult. The nearest approach, perhaps, as has been observed by Baldwin, to obtaining an accurate chronometric scale for ascertaining the age of the deposits of the Nile at a given point, was made near Memphis, at the statue of King Rameses. It is known that this statue was erected about the year 1260 B. C. In 1854 it had stood there 3,114 years. During that time the alluvium had collected to the depth of nine feet and four inches above its base, which was at the rate of about three and a half inches in each century. Mr. Horner found the alluvium, below the base of the statue, to be thirty feet deep, and pottery was found within four inches of the bottom of the alluvium. If the rate of accumulation previous to the building of the statue had been the same as subsequently, the formation of the alluvium began, at that point, about 11,660 years before the Christian era, and men lived there some 12,360 years ago, cultivating the then thin soil of the valley. But it would appear to be certain that the average deposit is so slight annually that many centuries more than those formerly quite universally received as the age of the world for the stage of mankind’s achievements must have passed since the work of man’s hands have been buried under these vast deposits of alluvium. Thus, geology insists, is the fact of man’s existence, long before the historic era, conclusively established.

AN OBJECT OF INTENSE INTEREST.

The Desert of Sahara presents some interesting facts of the same nature. It has already been stated that this part of Africa was ocean within a comparatively recent geological period. Tristram and several French officers of scientific attainments, who have made geological examinations of large portions of the desert have shown that the northern margin is lined with ancient sea-beaches and lines of terraces—the “rock-bound coasts” of the old ocean. Numerous salt-lakes exist in the desert which are tenanted by the common cockle. A species of Haligenes which inhabits the Gulf of Guinea is found in a salt lake in latitude 30 deg. north and longitude 7 deg. east, separated, therefore, from its present marine habitat by the whole extent of the great desert, and the vast expanse of Soudan and Guinea. Geologists hence conclude that the existing fauna, including man, occupied Africa long before the Sahara became dry land. Reference has been made in the preceding chapter to the supposed remarkably beneficent effect this great expanse of desert, heated sands, and hot air, has upon the climate, and consequently upon the civilization of Europe.

It is probable that from the fact that Sahara was about the last extensive portion of earth to be abandoned by the ocean, that the general opinion became prevalent that the continent of Africa was, geologically, the most recent of the grand divisions of the earth. Though supposed to be the oldest in civilization, it has been supposed to be the youngest in geological constitution. I am informed by scientific men that on account of recent investigations and reasonings, the opinion has for some time been gaining ground that Africa is likely to be shown to be the oldest part of the globe in both respects, and to have been the original birthplace of the race of man.

The negroid race, comprehending the Negroes, Hottentots, and Algutos, are, it is claimed by many scientists, the most ancient of all the types of mankind, and since their appearance on earth vast geographical changes have taken place. Continents have become ocean and sea has become land. “The negroes,” says Lubbock, “are essentially a non-navigating race, they build no ships, and even the canoes of the Feejeeans are evidently copied from those of the Polynesians. Now what is the geographical distribution of the race? They occupy all Africa south of Sahara, which neither they nor the rest of the true African fauna have ever crossed. And though they do not occur in Arabia, Persia, Hindoostan, Siam, or China, we find them in Madagascar, and in the Andaman Islands; not in Java, Sumatra, or Borneo, but in the Malay Peninsula, in the Phillippine Islands, New Guinea, the New Hebrides, New Caledonia, the Feejee Islands, and in Tasmania. This remarkable distribution is perhaps most easily explicable on the hypothesis that since the negroid race came into existence there must have been an immense tract of land or a chain of islands stretching from the eastern coast of Africa right across the Indian ocean; and secondly that the sea then occupied the area of the present great desert. In whatever manner, however, these facts are to be explained, they certainly indicate that the race is one of very great antiquity.” “It is manifest,” says Baldwin in his Pre-Historic Nations, “that Africa at a remote period was the theatre of great movements and mixtures of peoples and races, and that its interior countries had then a closer connection with the great civilizations of the world than at any time during the period called historical.” It is the opinion of this writer that the Cushite race—the Ethiopians of Scripture—appeared first in the work of civilization, and that in remote antiquity that people exerted a mighty and wide-spread influence in human affairs, whose traces are still visible from farther India to Norway. Nor is he by any means alone in the opinion that the Carthagenians, ages ago, sent their ships across the Atlantic to the American continent. The Cushites, or original Ethiopians originated in Arabia, but their descendents are still found in northern Africa from Egypt to Morocco. Of this race are the Tuariks, the robbers of the Great Desert, to this day among the most magnificent specimens of physical man to be found anywhere on the globe.

The final solution of these problems of the geological status of Africa, and the great antiquity of man can but be of the greatest interest to all thoughtful persons. Unquestionably their solution will be greatly hastened, should Dr. Livingstone succeed in the great enterprise upon which he is now engaged, and soon make known to the world the true sources of the Nile. His success therein would stimulate endeavor, study, exploration, and, it is to be hoped, comprehensive and systematic surveys of a continent the evidences of whose civilization in remote ages lie buried among the debris of countless centuries.

We know, from the imperfect investigations which have already been made, that cities have been engulfed in the sands of Sahara. We know that vast changes have taken place in the physical structure of the continent of Africa and of the world since the negro race first appeared. It is not improbable, therefore, that where for so many ages beasts of prey and savage tribes have occupied a land oppressed with heat and burdened with many ills, there may yet be found evidences of former civilization and power in greatest possible contrast to present barbarism and national weakness. And who shall say that when the face of the continent was changed, whether by a great convulsion or by a gradual process, some of the people did not migrate northward, cross the Mediterranean and populate the continent which has since become the abode of the highest civilization and the greatest intellectual culture? Who shall say that these races of remote antiquity were not possessed of culture and arts and literature placing them very high in the scale of civilization? Within the historic period those nations have passed away which were the acknowledged parents of modern culture and art. The power and versatility of the human mind, reason, eloquence, and poetry, were most sublimely illustrated by the Greeks, whose works still remain to benefit and instruct mankind. Yet the freedom and power of this wonderful people have for more than twenty centuries been annihilated. The people, in the eloquent diction of Macaulay, have degenerated into timid slaves; the language into a barbarous jargon; and the beautiful temples of Athens “have been given up to the successive depredations of Romans, Turks, and Scotchmen.” The vast empire of Rome has passed entirely away within a few centuries. She had herself annihilated Carthage leaving nothing, as we have seen, of the arts, literature, or institutions of a people whose ships had sailed on every wave from the Hellespont to the Baltic, and, not improbably, from the Mediterranean to the delta of the Mississippi. Other great nations are also known to have passed away or been destroyed, the nature of their civilization and institutions being left to conjecture based upon a few monuments or a few literary remains preserved by foreign writers. It being once established that man existed ages before what is commonly called the beginning of the historic period it would be simply logical, considering many national destructions which have occurred during the historic period, to conclude by analogy that races of remote antiquity flourished and passed away leaving no sign, which has been yet discovered, of their power and civilization. It is evident the historian Macaulay thinks it not improbable such may be the fate of England, and he expressly states in a well-known passage that the time may come when only a single naked fisherman may be seen in the river of the ten thousand masts. It is difficult, if not impossible, for mankind entirely to overcome the tendency to decay.

ARAB SLAVE TRADERS.

We shall presently see that Africa is a field upon which must soon be decided a great issue of politico-social importance; an issue which involves the abolition of polygamy, domestic slavery, and the suppression of the foreign slave trade. From what has gone before in this volume, it will have been seen that here, too, are likely to be most conclusively demonstrated the vast age of the world, the great antiquity of man, and the nature of his origin. In comparison of the settlement of this issue and the solution of these problems of science, even the discovery of the true sources of the Nile may be regarded as unimportant, except for the reason that Dr. Livingstone’s great achievement will arouse other men of science to similar sacrifices, labors, and fortitude. Thus Africa is found to present another remarkable contrast for our contemplation; for while civilization is there at a lower ebb than in any other grand division of the globe, the highest intellectual efforts of the most astute thinkers of the times are turning their best efforts thitherward, in the confident hope of greatly enlarging the sphere of human knowledge, and of extending the triumphs of science and civilization.

There are many, it is true, who imagine that the scientific inquiries which are being made in regard to the great age of the world, the races which existed long anterior to the historic period, and the origin of the human species are founded in a spirit of skepticism and hostility to Christian civilization, or, rather to Christianity as a religion. Doubtless there are many scientists who put no faith in Holy Writ, as much of it has been commonly understood. Others, and those among the most distinguished of men, are no less devout believers in Christianity than they are firm believers in the great age of the world and antiquity of man. The devotees of Christianity have in not a few instances mistaken an ally for an enemy. This was notably the fact, in an example which is here most appropriate, in the case of the modern origin of the science of astronomy. The Christian church, as then existing, pronounced as religious heresy the plain truth that the world moves, and that the sun neither rises nor sets, but is stationary—the sublime centre of a universe of planets and stars, and, perhaps, inhabited worlds, whose movements must be controlled, as the vast system must have been originated, by One of infinite wisdom and power and goodness. In due course of time it was discovered that astronomy did not militate against Christianity, and the church not only ceased putting astronomers in prison, but learned that the acceptance of all truth, come from whatever source it may, is a Christian duty. And many of the most distinguished astronomers have been no less earnest exemplars of the Christian system of religion than any monk who ever wore the pavements of a monastery and left the world no wiser or better than he found it.

As it was with astronomy, so it has been even of late years with the science of geology. The era of imprisonment for heresy had indeed passed by when men began to construct a comprehensive science on the study of rocks; but as their revelations became more extensive and more wonderful, it again appeared to many that here had arisen a formidable foe of Christianity, and the new science was assailed accordingly. It has not turned out that these disputants were as wise as they were zealous and as they were undoubtedly sincere. Though the sun never rises and never sets, we should be stupid indeed were we always, when speaking of his appearance on our horizon, or his disappearance therefrom, to state the fact in words of scientific accuracy. The world has never yet been slow enough justly to permit such waste of time and words. Not only the almanac-makers, but the most celebrated astronomers persist in saying that the sun rises and the sun sets. And, properly understood, it is perfectly true though scientifically false. To all appearance and for all practical purposes to the inhabitants of earth the sun does rise and set, and when one so says, whether inspired or uninspired, one simply conveys the idea that he intends to convey, and this is the province of language. As astronomy appeared to be utterly opposed by certain expressions in Scripture, but was found not to be, upon more liberal construction of the language, as well as more philosophical, so geology appeared to be, in its apparent demonstration of the vast age of the world, and, later, of the great antiquity of man, hostile to the received canons of the church, and especially subversive of the Mosaic account of creation and the generally received system of chronology. The conflicts thus arising have dissipated many erroneous theological constructions and dogmas, but they have in no manner affected the foundations of Christianity. There are many eminent geologists who are earnest Christians, and though Dr. Livingstone himself has done geology incalculable service he has done Christianity incalculably more. It may well be doubted whether any single theologian of the age has conferred more valuable service upon Christianity than Hugh Miller, the great geologist of Scotland, whose scientific works are, perhaps, the most fascinating of any in the English language.

There can be, then, no well-grounded fear of science overturning Christianity. It is more likely thereby to be in the end not only more thoroughly and correctly understood, but more firmly established and more generally adopted. Even the inquiry which is now receiving so much attention from men of thought—that into the origin of man—need not be deemed as fraught with any real danger to the system which has given the world its present civilization. Were it possible to establish Mr. Darwin’s theory of evolution—and that it is more than a theory cannot be claimed for it by its most devoted advocate—and establish man’s origin in the ape, still would the act of his creation into man from ape be an act of infinite power and goodness. For the infinite power and goodness of the act consist in the creation, by some means, of a being of intellectual and moral attributes. The act of divine power is in breathing into the nostrils the breath of life, and causing the being to become a living soul. Even Mr. Darwin will not dispute that the ape was in the long ages evolved from dust, nor that, so far as science has shown or probably ever can show, there is no being in the universe with capacity to evolve thought except only God, as shown in His manifold works, and man.

Whatever may be the result, therefore, of the interesting inquiries in commerce, religion, geography, geology, ethnology which now are being more and more directed toward Africa with each passing year, we may quite safely conclude, judging from the results of the past, that Christianity will come forth out of the conflicts that may arise, whether they be scientific or of other nature, with renewed beauty and power; with more liberal and enlightened views, doubtless, upon some questions which have been erroneously considered, but with greater influence on this account, and with brighter prospects of more speedily than might have been but for these conflicts extending the rule of her pure and beneficent morality among all the nations and tribes of men.