nent, as it does at this day in the northern countries of Sweden, Norway and Lapland adjacent to it, its particles may have been kept in folution by the fixed air, and the argillaceous, filiceous and carbonaceous particles may have been long fufpended. Thefe muddy waters mixing with thofe impregnated with bitumen, the following combina tions must have taken place: 1°. If carbonic matter was alfo contained in the water, this uniting to the bitumen must have run into maffes no longer fufpenfible in water, and formed ftrata of coal. 240. The calces of iron by the contact of bitumen were in great measure gradually reduced, and together with the argillaceous and filiceous precipitated on the fummits of feveral of the mountains not yet emerged, and thus formed bafaltic maffes, that during deficcation fplit into columns; in other places they covered the carbonaceous maffes already depofited, and by abforbing much of their bitumen rendered them lefs inflammable, and hence the connexion which the fagacious Werner obferved between bafalts and coal. The fixed or oxygen air, erupting from many of them, formed thofe cavities, which being filled by the fubfequent infiltration of fuch of their ingredients as were fuperfluous to their bafaltic ftate, formed chalcedonies, zeoliths, olivins, bafaltines, fpars, &c. Hence moft of the mountains of Sweden that afford iron, afford alfo bitumen. Hence alfo the afphalt found with trap, and under bafalts, and in balls chalcedony found in trap. have fometimes been found in them; fome argillaceous or fandstone ftrata may also have been depofited at this period. "On this account however of the formation of the bafalts which crown the fummits of feveral lofty peaks, I lay no more ftrefs than it can juftly bear; I deliver it barely as an hypothefis more plaufible than many others. "It has been objected to the Mofaic account that the countries near Ararat are too cold to bear olive trees. Tournefort, who first made this objection, fhould recollect, that at this early period the Cafpian and Euxine feas were joined, as he himfelf has well proved. This circumftance furely fitted a country lying in the 38th degree of latitude to produce olives (which now grow in much higher latitudes), at prefent chilled only by its diftance from the fea. "A more plaufible objection a rifes from the difficulty of collecting and feeding all the various fpecies of animals now known, fome of which can exift only in the hotteft, and others only in the coldest climates; it does not however appear to me neceflary to fuppofe that any others were collected in the ark but those moft neceflary for the use of man, and thofe only of the graminivorous or granivorous claffes, the others were moft probably of fub. fequent creation. The univerfality of the exprethons, Gen. chap. vi. ver. 19. Of every living thing, of all flesh, two of every fort offhait thou bring into the ark," feem to me to imply no more than the fame general expreffions do in Gen. chap. i. ver. 30. And to every beaft of the earth, and to every fowl of the air, have I giv en every green herb for meat;" where it is certain that only grami "This I take to be the laft fcene of this dreadful catastrophe, and hence no hells are found in thefe bafalts, they having been previoufly depofited, though fome other lighter marine vegetable remains nivorous nivorous animals are meant. At this early period ravenous animals were not only not neceffary, but would have been even deftructive to those who had juft ob tained existence, and probably not in great numbers. They only became neceffary when the graminivorous had multiplied to fo great a degree that their carcaffes would have spread infection. Hence they appear to me to have been of pofterior creation; and to this alfo I attribute the existence of those that are peculiar to America and the tor. rid and frigid zones. "The atmosphere itself muft have been exceedingly altered by the confequences of the flood. Soon after the creation of vegetables, and in proportion as they grew and multiplied, vaft quantities of oxygen must have been thrown off by them into the then exifting atmosphere without any proportional counteracting diminution from the refpiration or putrifaction of animals, as these were created only in pairs, and multiplied more flowly; hence it must have been much purer than at prefent; and to this circumstance perhaps the longevity of the ante diluvians may in great measure be attributed. After the flood the ftate of things was perfectly reverfed, the furface of the earth was co- . vered with dead and putrifying land animals and fish, which copiously abforbed the oxygenous part of the atmosphere and fupplied only mephitic and fixed air; thus the atmofphere was probably brought to its actual ftate, containing little more than one-fourth of pure air and nearly three-fourths of mephitic. Hence the conftitution of men must have been weakened, and the lives of their enfeebled pofterity gradually reduced to their prefent ftandard. To avoid these exhalations it is probable that the human race continued for a long time to inhabit the more elevated mountainous tracts. Domestic difturbances in Noah's family, briefly mentioned in holy writ, probably induced him to move with fuch of his defcendants as were most attached to him to the regions he inhabited before the flood, in the vicinity of China, and hence the early origin of the Chinese monarchy." OBSERVATIONS on the PHYSICAL and POLITICAL GEOGRAPHY of NORTH AFRICA, by JAMES RENNEL, Efq. F. R. S. [From GEOGRAPHICAL ILLUSTRATIONS of Mr. PARK'S JOURNEY, in the PROCEEDINGS of the AFRICAN ASSOCIATION, 1798.] “T O our view, North Africa appears to be compofed of three distinct parts, or members. The first and fmalleft is a fertile region along the Mediterranean, lying oppofite to Spain, France, and Italy (commonly diftinguifhed by the name of Barbary); and which, could we fuppofe the western bafin of the Mediterranean to have once been dry land (bating a lake or recipient for the furrounding rivers), might be regarded as a part of Europe; as poffeffing much more of the European than the African cha racter. "The "The fecond part is what may be deemed the body of North Africa, comprised between Cape Verd and the Red Sea, on the eaft and weft; and having the Great Defert (or Sahara) and its members, on the north; the Ethiopic ocean and South Africa, on the oppofite fide. The prominent feature of this immenfe region is a vast belt of elevated land of great breadth, often fwelling into lofty mountains, and running generally from weft to caft, about the tenth degree of latitude. Its western extremity feems to be Cape Verd; the mountains of Abyffinia, the eastern. To the north, its ramifications are neither numerous nor extensive, if we except the elevated tract which turns the Nile to the northward beyond Abyffinia. Towards the fouth, no particulars are known, fave that a multitude of rivers, fome of them very large, defcend from that fide and join the Atlantic and Ethiopic feas, from the Rio Grande on the weft to Cape Lopez on the east; proving inconteftably that by far the greatest proportion of rain water falls on that fide during the periodical feason of the S. W. winds; which correfponds in all its circumftances with the fame monfoon in India *. "To the north of this belt, with the exception of the Egyptian Nile, the waters conform generally to the direction of the high land; paffing at no great distance (comparative ly) from its bafe to the right and left; as if the furface of the Sahara had a general dip to the fouthward +. Thefe rivers moreover receive all their fupplies from the fouth; no ftreams of any bulk being collected in the defert. "In order to produce this effect, there must neceffarily be a vast hollow in the interior of Africa, between the high land of Nubia on the eaft, and Manding on the weft; and of which the mountains and defert form the other two fides. Nor is this ftate of things unexampled in the other continents. In Afia, the hollow, to whofe waters the Cafpian and Aral ferve as recipients, is no lefs extenfive than the one juft mentioned; reckoning from the fources of the Wolga to thofe of the Oxus (which latter has ever communicated with the Cafpian, either throughout the year or during a part of it); the difference is, that in Afia a greater portion of the hollow is filled up with water than in Africa. "The third part is of course the Great Defert (or Sahara) and its members; confifting of the_leffer deferts of Bornou, Bilma, Barca, Sort, &c. This may be confidered as an ocean of fandt, prefenting a furface equal in extent to about one half of Europe, and having its gulfs and bays; as also its iflands fertile in groves and pastures, and in many inftances containing a great population fubject to order and regular government. The great body or western divifion of this * A ridge ftretches to the fouth through the middle of South Africa, and forms an impenetrable barrier between the two coafts. M. Correa de Serra informs me, that the Portuguese in Congo and Angola have never been able to penetrate to the coast of the Indian Ocean. "Mr. Bruce learned (vol. iii. p. 668.) that a high chain of mountains from 6° runs fouthward through the middle of Africa. He fuppofes the gold of Sofala to be drawn from thefe mountains. (P. 669.) Circumftances have fhewn, that it declines to the caftward alfo." "A wild expanfe of lifelefs fand and fky! THOMSON. ocean, ocean, comprised between Fezzan and the Atlantic, is no lefs than fifty caravan journies across from north to fouth; or from 750 to 800 German miles; and double that extent in length without doubt the largest defert in the world. This divifion contains but a fcanty portion of iflands (or oafes), and those alfo of fmall extent; but the eastern divifion has many, and fome of them very large. Fezzan, Gadamis, Taboo, Ghanat, Agadez, Augela, Berdoa, are amongst the principal ones: befides which there are a vaft number of fmall ones. In effect this is the part of Africa alluded to by Strabo*, when he fays from Cneius Pifo, that Africa may be compared to a leopard's skin. I conceive the reason why the oafes are more common here than in the weft, is, that the ftratum of fand is fhallower from its furface to that of the earth which it covers; in other words, that the water contained in that earth is nearer to the furface; as in most of the oafes it fprings up fpontaneously + Can any part of the caufe be affigned to the prevalent eafterly winds, which, by driving the finer particles of fand to leeward, may have heaped it up to a higher level in the Sahara than elsewhere? "The fprings no doubt have "* Page 130." produced the oafes themfelves, by enabling useful vegetables to flourith, and confequently population. to be established. That the Defert has a dip towards the east as well as the fouth, feems to be proved by the courfe of the Niger alfo. Moreover the highest points of North Africa, that is to fay, the mountains of Mandinga and Atlas, are fituated very far to the weft. "The Defert for the most part abounds with falt. But we hear of falt mines only in the part contiguous to Nigritia, from whence falt is drawn for the ufe of thofe countries as well as of the Moorish ftates adjoining; there being no falt in the negro countries fouth of the Niger . There are falt lakes also in the eastern part of the Defert. "The great ridge of mountains and its branches are very productive in gold; but more particularly in the quarters oppofite to Manding and Bambouk on the west, and Wangara on the east. It may perhaps admit of a doubt, whether the gold is brought down at the prefent time by the numerous fountains that form the heads of the Niger and Senegal rivers; or whether it has been depofited in the lower parts of their beds at an earlier period of the world; and that the fearch, inftead of being facilitated by the periodical floods, "Water is found at the depth of a few feet in Fezzan (African Affoc. Q. p. 96. O. p. 146) The fame is faid by Pliny, concerning this quarter of Africa; lib. v. c. 5. But farther to the N. W. on the edge of the defert, and in the country of Wadreag in particular, (Shaw, p. 135.) wells are dug to an amazing depth, and water mixed with fine fand fprings up fuddenly, and fometimes fatally to the workmen. The Doctor tells us that the people call this abyfs of fand and water the fea below ground.' Exactly the fame ftate of things exifts in the country round London, where the fand has in feveral cafes nearly filled up the wells. (See Phil. Tranf. for 1797.) The famous well lately dug by earl Spencer (at Wimbledon), of more than 560 feet in depth, has feveral hun dred feet of fand in it." "This quality of the African Defert was familiarly known to Herodotus. (Melpom e. 181, et feq.) He knew alfo that there was falt in abundance in the northern parts. But, as the inhabitants in that quarter can furnish themselves with falt of a better quality from the fea, the mines are not wrought." is on the contrary only to be purfued with effect when the waters are low. "Tombuctoo is reckoned the mart of the Mandinga gold, from whence it is diftributed over the northern quarters of Africa by the merchants of Tunis, Tripoly, Fezzan, and Morocco: all of whom refort to Tombuctoo. Most of it no doubt afterwards finds its way into Europe. It may be remarked alfo, that the gold coaft of Guinea (fo called doubtlefs from its being the place of traffic for gold duft) is fituated nearly oppofite to Manding: but whether the gold brought thither has been washed out of the mountains by the northern or fouthern streams, I know not: it may be both. Degombah, another country faid to be very productive in gold †, muft by its fituation lie directly oppofite to the gold coaft: for it lies immediately to the east of Kong (the Gonjah of Mr. Beaufoy and the Conche of d'Anville ). The people of Fezzan trade to "The triangular hilly tract above commemorated (p. 71 of the Illuftrations"), which projects north. ward from the highest part of the belt, and contains Manding, Bambouk, &c. is also abundant in gold; particularly in the quarter towards Bambouk, where it is found in mines; and that chiefly in the middle level §. (See alfo p. 71.) 'Wangara appears to have been in its time nearly as rich as Manding in this metal. The Arabs name it belad al tebr, or the country of gold .' Edrifi, Ibn Al Wardi, and Leo, bear teftimony to its riches. They fay that the gold is found in the fands after the periodical inundation of the Niger (which is gene ral over the country) is abated. Leo alone ** fays, that the gold is found in the fouthern quarter of the kingdom; which appears very probable, as the mountains lie on that fide: fo that it may be con "Some writers have faid, that there are gold mines in the neighbourhood of Mina, on the gold coaft; others, that the gold is rolled down by the rivers to that neighbourhood. Both may be true. But, on the other hand, it is faid that the gold of Wangara is alfo brought for fale to the fouthern coaft. "It is difficult to conceive any other adequate caufe, than the exchange of the gold of the inland countries, for the introduction of fo vait a quantity of kowry fhells, which are carried from Europe to the coast of Guinea, and pafs for fmall money in the countries along the Niger from Bambara to Kaffina, both inclufive. "I am informed from authority, that about 100 tons of kowries are annually shipped from England alone to Guinea. Thefe are originally imported from the Maldive inlands into Bengal; and from Bengal into England. In Bengal 2400 more or lefs are equal to a fhilling and yet, notwithstanding the incredible fmallness of the denomination, fome article in the market may be purchased for a fingle kowry. But in the inland parts of Africa they are about ten times as dear, varying from 220 to 280. Mr. Beaufoy was told, that in Kaffina they were at the rate of about 250. And Mr. Park reports, that they are about the fame price at Sego: but cheaper at Tombuctoo, which is about the centre of the kowry country: dearer towards Manding, which is the western extremity of it. Hence they are probably carried in the first intìance to Tombuctoo, the gold market; and thence difiributed to the east and west. Their circulation feems to be confined between Bornou and Manding. In Bornou they have a coinage of base metal," "African Affoc. Q. p. 176. O. p. 264.” "Mr. Park fays, that Kong fignifies mountain in the Mandinga language; which language is in ufe from the frontier of Bambara to the western fea, "Labat, vol. iv. ch. 2. "Bakui, and Herbelot; article Vankara." 66 ག See Edrifi in particular, pages 11 and 12." *** Page 254. cluded, |