The learned Reinaud, in his recent excellent translation of Abulfeda (T. ii., P. i., p. 81–82), considers it probable that the Ptolemaic interpretation of the name, by “Mountains of the Moon” (ὅρη σεληναῖα), was that originally adopted by the Arabian writers. He remarks that in the Moschtarek of Yakut, and in Ibn-Said, the mountains are written al-Komr, and that Yakut writes in the same way the name of the island of Zendj (Zanguebar). The Abyssinian traveller Beke, in his learned critical memoir on the Nile and its tributaries (Journal of the Royal Geographical Society of London, vol. xvii. 1847, p. 74–76), seeks to prove that Ptolemy had merely formed his σελήνης ὅρος from a native name, for which he was indebted to intelligence received through the medium of the extensive commercial intercourse which prevailed. He says, “Ptolemy knew that the Nile rises in the mountainous country of Moezi; and in the languages which extend over a great portion of South Africa (for example, in the languages of Congo, Monjou, and Mozambique), the word Moezi signifies the moon. A great south-western country was called Mono-Muezi, or Mani-Moezi, i. e. the land of the king of Moezi (of the king of the Moon country), for in the same family of languages in which Moezi or Muezi signifies the Moon, Mono or Mani signifies a king. Alvarez, in the Viaggio nella Ethiopia (Ramusio, vol. i, p. 249,) speaks of the ‘regne di Manicongo,’ the kingdom of the king of Congo.” Beke’s opponent, Ayrton, seeks the origin of the White Nile (Bahr el Abiad), not as do Arnaud, Werne, and Beke, near the equator, or even south of it (and in 29° E. long. from Paris, or 31° 22′ from Greenwich), but with Antoine d’Abbadie far to the north-east, in the Godjeb and Gibbe of Eneara (Iniara); therefore in the high mountains of Habesch, in 7° 20′ N. latitude, and 33° E. long. from Paris, or 35° 22′ from Greenwich. He conjectures that the Arabs, from a similarity of sound, may have interpreted the native name Gamaro belonging to the Abyssinian mountains, in the south-west of Gaka in which the Godjeb (or White Nile?) has its source, to mean Moon Mountains (Djebel al-Kamar); so that Ptolemy himself, familiar with the intercourse between Abyssinia and the Indian Ocean, may have taken the Semitic version, given by early Arab immigrants. (Compare Ayrton in the Journal of the Royal Geogr. Soc. vol. xviii. 1848, p. 53, 55, and 59–63, with Fred. Werne’s instructive expedition for the discovery of the sources of the Nile, Exped. zur Entd. der Nil-Quellen, 1848, S. 534–536.)
The lively interest which has again been excited in England for the discovery of the most southern sources of the Nile, induced the above-named Abyssinian traveller, Charles Beke, at the recent meeting of the British Association for the Advancement of Science, held at Swansea, August 1848, to develop more in detail his ideas respecting the connection between the Mountains of the Moon and the Mountains of Habesch. He says:—“The Abyssinian elevated plain, generally above 8000 feet high, extends towards the south to nearly 9° or 10° N. latitude. The eastern declivity of the highlands has to the inhabitants of the coast the appearance of a mountain chain. The plateau at its southern extremity passes into the Mountains of the Moon, which run, not east and west, but parallel to the coast, or from NNE. to SSW.; extending from 10° N. to 5° S. latitude. The sources of the White Nile are situated in the Mono-Moezi country, probably in 2½° S., not far from where the river Sabaki, on the eastern side of the Mountains of the Moon, falls into the Indian Ocean near Melindeh, north of Mombaza. Last autumn (1847) the two Abyssinian missionaries Rebmann and Krapf were still on the coast of Mombaza. They have established in the vicinity, among the Wakamba tribe, a missionary station called Rabbay Empie, which promises to be very useful also for geographical discovery. Families belonging to the Wakamba tribe have advanced to the west five or six hundred miles into the interior of the country, as far as the upper course of the river Lusidji, the great lake Nyassi or Zambeze (5° S. lat.?), and the sources of the Nile which are not far distant. An expedition to these sources, which Herr Friedrich Bialloblotzky, of Hanover, is preparing to undertake, (by the advice of Beke), is to set out from Mombaza. The Nile coming from the west referred to by the ancients is probably the Bahr-el-Ghazal, or Keilah, which falls into the Nile in 9° N. lat., above the mouth of the Godjeb or Sobat.”
Russegger’s scientific expedition,—which by Mehemet Ali’s desire was sent to the gold-washings of Fazokl on the Blue (Green) Nile, Bahr-el-Azrek, in 1837 and 1838,—had made the existence of the “Mountains of the Moon” appear very doubtful. The Blue Nile, the Astapus of Ptolemy, issuing from the lake of Coloe (now called lake Tzana) winds from amongst the colossal Abyssinian mountains; but towards the south-west an extensive low tract of country appears. The three exploring expeditions sent by the Egyptian government, (one in November 1839 from Chartum to the confluence of the Blue and the White Nile, under the command of Selim Bimbashi; another in the autumn of 1840, which was accompanied by the French engineers Arnaud, Sabatier, and Thibaud; and a third in August 1841), first unveiled the high mountains which, between the parallels of 6°-4°, and probably still farther to the south, run at first from west to east, and afterwards from north-west to south-east, and approach the left bank of the Bahr-el-Abiad. The second of Mehemet Ali’s expeditions first saw the mountain chain, according to Werne’s account, in lat. 11⅓° where Gebel Abul and Gebel Kutak rise to 3400 (3623 Eng.) feet. The high land continued and approached nearer to the river more to the south, between 4¾° lat., to the parallel of the island of Tschenker in 4° 4′, where the expedition of Commander Selim and Feizulla Effendi terminated. The shallow river makes its way between rocks, and detached mountains rise again in the country of Bari to 3000 (3197 Eng.) feet. These probably belong to the Mountains of the Moon as represented in our most recent maps, although they are not indeed mountains covered with perpetual snow such as Ptolemy had described (lib. iv. cap. 9). The limit of perpetual snow in these latitudes would not certainly be found below an elevation of 14500 (15450 Eng.) feet. Perhaps Ptolemy transferred to the country of the sources of the White Nile the knowledge which he may have had of the high mountains of Habesch, which are nearer to Upper Egypt and to the Red Sea. In Godiam, Kaffa, Miecha, and Sami, the Abyssinian mountains rise to 10000 and 14000 (10657 and 14920 Eng.) feet, according to exact measurements; not according to Bruce, who gives the elevation of Chartum exceedingly wide of the truth, i. e., 4730 (5041 Eng.) feet, instead of 1430 (1524 Eng.) feet! Rüppell, one of the most accurate observers of the present day, found Abba Jaret, in 13° 10′ of latitude, only 66 (70 Eng.) feet lower than Mont Blanc. (Compare Rüppell, Reise in Abyssinien, Bd. i. S. 414, and Bd. ii. S. 443). Rüppell found, adjoining the Buahat, an elevated plain 13080 (13939 Eng.) feet above the Red Sea, barely covered with a small quantity of fresh fallen snow (Humboldt, Asie Centrale, T. iii. p. 272). The celebrated inscription of Adulis, which Niebuhr considers to be somewhat later than Juba and than Augustus, also speaks of Abyssinian snow “that reaches to the knees.” This is, I believe, the earliest mention in antiquity of snow within the tropics (Asie Centrale, T. iii. p. 235); as the Paropanisus is 12° of latitude north of the northern limit of the torrid zone.
Zimmermann’s map of the countries about the Upper Nile shews the dividing line which determines the basin of the Great River, and separates it on the south-east from the domain of the rivers which flow into the Indian Ocean;—that is to say, from the Doara, which enters the sea north of Magadoxo; from the Teb, which has its embouchure on the Amber coast, near Ogda; and from the Goschop, whose abundant stream is formed by the confluence of the Gibu and the Zebi, and which he distinguishes from the Godjeb, rendered celebrated since 1839 by Antoine d’Abbadie, the missionary Krapf, and Beke. These results of the travels of Beke, Krapf, Isenberg, Russegger, Rüppell, Abbadie, and Werne, brought together and shewn in the most comprehensive and convenient manner by Zimmermann, were hailed by me on their appearance in 1843 with the most lively joy, as expressed in a letter to Carl Ritter. “If,” I wrote to him, “a life prolonged to an advanced period brings with it several inconveniences to the individual, and perhaps some even to those who live with him, there is a compensation in the delight of being able to compare older states of knowledge with that which now exists, and to see great advances in knowledge grow and develope themselves under our eyes in departments where all had long slumbered in inactivity, with the exception, perhaps, of attempts by hypercriticism to render previous acquisitions doubtful. This enjoyment has from time to time fallen to our share, yours and mine, in our geographical studies, and this particularly in reference to those very parts of the world which formerly could only be treated of with timid hesitating uncertainty. The conformation of a continent depends in its leading traits on several plastic relations which are usually among the latest to be discovered and unravelled. A new and excellent work of our friend Carl Zimmermann, on the upper country of the Nile and the eastern parts of central Africa, has again brought these considerations very vividly before me. His new map shews in the clearest manner to the eye, by means of a particular method of shading, what is still unknown, and what, by the courage and perseverance of travellers of all nations,—among whom our own countrymen happily hold an important place,—has been already disclosed to us. It is a valuable service, and one which opens the way for farther advances and more comprehensive inferences, when persons, thoroughly acquainted with the existing, often widely scattered, materials,—men who do not merely draw and compile, but compare, select, and, wherever it is possible, check and control the routes of travellers by astronomical determinations of position,—undertake to represent graphically the results of the elements of knowledge possessed at the time. Those who have themselves given to the world so much as you have done, have an especial right to expect much; since their combinations have largely augmented the number of connecting points; yet I believe that when you executed your great work on Africa in 1822 you could hardly have expected so many accessions as we have now received.” The knowledge acquired is, indeed, often only that of rivers, their direction, their branches, and the various synonyms by which they are called in dialects belonging to different families of languages; but rivers reveal to us by their course the form of the surface of the earth, and are at once the nourishers of vegetation, the channels of intercourse between men, and pregnant with unknown influences on the future.
The northerly course of the White Nile, and the south-easterly course of the great Goschop, would indicate that a swelling of the ground separates the domains or basins of these rivers. We know, indeed, but imperfectly, how such a swelling or elevation may be connected with the mountains of Habesch, and in what manner it may be continued southward beyond the equator. Probably, and this is also the opinion of my friend Carl Ritter, the Lupata mountains, which, according to the excellent Wilhelm Peters, extend to 26° S. latitude, are connected with the elevated parts of the Earth’s surface on the north side of the equator, (or with the Abyssinian mountains), by the mountains of the Moon. The word “Lupata,” we learn from the last-named African traveller, is used in the language of Tette as an adjective, meaning “closed.” The chain of mountains would thus be called the “closed” or “barred.” “The Lupata chain, of Portuguese writers,” says Peters, “is about 90 legoas or leagues from the mouth of the Zambeze, and is only about two thousand feet high. The direction of this mountain rampart is north and south, but with occasional bends alternately to the east and to the west. It is sometimes interrupted by plains. Along the whole of the Zanzibar coast, the traders into the interior speak of this long but not very elevated ridge, which extends from 6° to 26° S. latitude, as far as the Factory of Lourenzo-Marques, on the Rio de Espiritu Santo (in the Bay da Lagoa, or Delagoa Bay of the English). The farther the Lupata chain advances towards the south, the nearer it approaches the coast, from which it is only fifteen legoas distant at Lourenzo-Marques.”
[24] p. 12.—“Caused by the great revolving current.”
In the northern part of the Atlantic, between Europe, North Africa, and the New Continent, the waters of the ocean are driven round in a true revolving current, or circle. This general current,—which, from its cause, might be called a “Rotation Current,”—moves between the tropics, as is well known, with the trade wind, from east to west. It accelerates the passage of ships sailing from the Canaries to South America, and makes it almost impossible to sail “up stream,” or in a direct line from Cartagena de Indias to Cumana. This set to the west, attributed to the trade winds, receives, however, in the Caribbean Sea, the accession of a much stronger movement, originating in a very remote cause, which was discovered as early as 1560 by Sir Humphrey Gilbert, (Hakluyt, Voyages, vol. iii. p. 14), and developed with greater certainty by Rennell in 1832. The Mosambique current, flowing from north to south between Madagascar and the east coast of Africa, sets on the Lagullas Bank, turns on the north side of it round the south point of Africa, and advances with much force up the western coast of the Continent to a little beyond the equator near the Island of St. Thomas. It gives at the same time a north-westerly direction to a part of the water of the South Atlantic, causing it to strike Cape St. Augustin, and to follow the coast of Guiana to beyond the mouth of the Orinoco, the Boca del Drago, and the coast of Paria. (Rennell, Investigation of the Currents of the Atlantic Ocean, 1832, p. 96 and 136.) The New Continent, from the Isthmus of Panama to the northern part of Mexico, opposes a barrier to the farther continuance of this movement of the waters, and thus the current is constrained to assume a northerly course off Veragua, and thence to follow the windings of the coast of Costa Rica, Mosquito, Campeachy, and Tabasco. The waters which enter the Mexican Gulf between Cape Catoche of Yucatan and Cape San Antonio of Cuba, after completing a great rotatory movement or circuit, by Vera Cruz, Tamiagua, the mouth of the Rio Bravo del Norte, and that of the Mississipi, force their way northwards through the Bahama Channel, and re-issue into the open ocean. Here they form the well-known “Gulf Stream,” a current or river of warm and rapidly moving water, flowing in an oblique or diagonal direction carrying it farther and farther from the North American coast. Ships from Europe bound for this coast, when uncertain in respect to their longitude, are enabled by this oblique direction of the current to direct their course, as soon as they reach the Gulf Stream, by observations of latitude only. The position of this great current was first indicated with accuracy by Franklin, Williams, and Pownall.
From the 41st degree of latitude, the river of warm water, which has been gradually diminishing in rapidity and increasing in breadth, turns suddenly to the east. It almost touches the southern edge of the great Newfoundland bank, where I found the greatest amount of difference between the temperature of the warm water of the Gulf stream, and that of the waters resting on the banks and subjected thereby to a cooling process. Before the stream reaches the westernmost of the Azores it divides into two branches, one of which, at least at certain seasons, advances towards Ireland and Norway, and the other towards the Canaries and the West Coast of Africa. This Atlantic rotatory movement, (described by me in more detail in the first volume of my Voyage to the Equinoctial Regions), explains the possibility of trunks of South American and West Indian trees being carried, in spite of the trade winds, to the coasts of the Canary Islands, and stranded there. I have made many experiments on the temperature of the Gulf Stream in the vicinity of the Banks of Newfoundland. The Stream brings the warmer water of lower latitudes into more northern regions with much rapidity, and I have thus found its temperature two or three degrees of Reaumur (5° to 7° Fah.) higher than that of the adjacent unmoved masses of water, which form as it were the banks of the warm oceanic river.
The flying fish of the tropics (Exocetus volitans) accompanies the warm water of the Gulf Stream far into the temperate zone. Floating sea-weed (Fucus natans), chiefly taken up by the stream in the Gulf of Mexico, shews when a ship is entering the current, and the arrangement of the branches of the sea-weed shews the direction of the movement of the water. The mainmast of the English ship of war, the Tilbury, destroyed by fire on the coast of San Domingo, was carried by the Gulf Stream to the north coast of Scotland. Even casks filled with palm oil, the remains of the cargo of a ship wrecked off Cape Lopez on the coast of Africa, were carried in the same manner to Scotland[*], after having twice traversed the whole breadth of the Atlantic; once from east to west with the equatorial current between 2° and 12° N. lat., and once from west to east by the aid of the Gulf Stream, between 45° and 55° N. lat. Rennell, in p. 347 of the “Investigation of Currents,” relates the voyage of a bottle with papers enclosed, thrown overboard by the English ship Newcastle on the 20th of January, 1819, in lat. 38° 52′, and long. 63° 58′, which was picked up on the 2nd of June, 1820, at the Rosses, (near the Island of Arran), on the west coast of Ireland. A short time before my arrival at Teneriffe a stem of South American cedar (Cedrela odorata), well covered with lichens, had been cast ashore in the harbour of Santa Cruz.
Effects of the Gulf Stream in stranding on the Islands of Fayal, Flores, and Corvo in the Azores, bamboos, artificially cut pieces of wood, trunks of an unknown species of Pine from Mexico and the West Indian Islands, and corpses of men of unknown race with unusually broad faces, contributed to the discovery of America, by confirming Columbus in his belief of the existence to the westward of Asiatic countries and islands at no impassable distance. The great discoverer even heard from the lips of settlers near the Cape de la Verga in the Azores, of some, “who, in sailing westward, had met decked or covered boats, manned by persons of strange and foreign appearance, and built apparently in such a manner that they could not founder,—almadias con casa movediza que nunca se hunden.” There is highly credible and well-confirmed testimony to the fact, much as it has long been doubted, of natives of America, (probably Esquimaux from Greenland or Labrador), carried by currents or driven by storms from the North West, having actually crossed the Atlantic in their canoes and reached our shores. James Wallace, in his “Account of the Islands of Orkney, (1700, p. 60),” relates, that in 1682 a Greenlander was seen in his boat off the South Point of the Island of Eda by several persons, who did not succeed in bringing him to shore. In 1684, a Greenland fisherman appeared in his boat off the Island of Westram. In the church at Barra there was suspended an Esquimaux boat, driven thither by currents and tempests. The inhabitants of the Orkneys call Greenlanders so appearing among them Finns or “Finnmen.”