657 



ATLAS. 



of Mexico ; but the quantity is so great that it is reasonably supposed 

 that most of it must be produced in the Atlantic itself at the bottom 

 of the sea. It appears to be produced in considerable quantities on 

 the Bahama banks. 



It is a known fact that the waters of the Atlantic Ocean in different 

 parts contain different quantities of salt ; and several persons have 

 been at some pains to ascertain the amount of this difference, but no 

 satisfactory results have yet been attained. \Ve know only with cer- 

 tainty that the specific gravity of the sea-water is less near the poles 

 than between the tropics and under the equator ; but how great that 

 difference is remains uncertain. Captain Scoresby found the specific 

 gravity of the sea- water near the coast of Greenland to be between 1 '025 9 

 and 1 "0270 ; and others have observed it between the tropics to be 

 1-0297, and near the equator even V0578 ; but the latter observation 

 is rendered doubtful by others which gave a different result. 



Another remarkable fact is the difference between the specific gravity 

 of the water of the Baltic and Mediterranean seas and the Atlantic 

 Ocean. That of the Baltic contains only one-sixth of the salt which is 

 found dissolved in the Ocean, its specific gravity being on an average 

 not mure than 1-0049. The Mediterranean Sea contains somewhat 

 more salt than the Ocean : to the east of the Strait of Gibraltar the 

 specific gravity of the sea- water is 1-0338 ; whilst between Cape St. 

 Vincent and Cape Cantin it was found to be only 1-0294. 



One of the subjects to which the American naval officers engaged in 

 the survey of the Atlantic have directed a good deal of their attention 

 is that of endeavouring to ascertain the greatest depths of the ocean. 

 They succeeded in obtaining very deep soundings, the greatest being 

 that obtained by Lieutenant Walsh, who in 31" 59' N. lat., 58 43' 

 W. long., sounded to 5700 fathoms (34,200 feet, or 5'6 geographical 

 miles) without finding bottom. This was the greatest depth which 

 had then been attained; but it has since been exceeded by an English 

 officer, Captain H. M. Denham, of H.M.S. Herald, who on the 30th of 

 October, 1852, in 36 49' S. lat. 37 6' W. long., found bottom at a 

 depth of 7706 fathoms (46,236 feet, or 7'6 geographical miles), which 

 id 3 geographical miles more than the highest points of the Himalaya 

 Mountains are above the surface of the sea. These soundings, if they 

 could be depended on, would sufficiently prove what has long been 

 supposed, that the ocean has depths very far surpassing the loftiest 

 elevations on the surface of the earth. It is right however to add 

 that the accuracy of these deep-sea soundings has been disputed, 

 although the greatest care was taken to ensure their correctness. 



We mentioned that one of the points to which the United States 

 government directed the particular attention of the masters of whalers 

 of which there are in the American whale fishery upwards of 600, 

 manned by 15,000 seamen was the localities in which the sperm and 

 ' right ' whales were met with. The results deduced from a careful 

 comparison of their logs are so remarkable as to deserve quoting in 

 the words of Lieutenant Maury's Report : 



" As observation after observation in such an immense field was 

 recorded day after day, with the most untiring industry, and as the 

 oft-repeated process finally began to express a meaning, I was sur- 

 prised to find the lines for entering the right whales through certain 

 districts of the ocean were blanks from one side of the chart to the 

 other. Finally it was discovered that the torrid zone is to this 

 animal forbidden ground, and that it is physically as impossible for 

 him to cross the equator as it would be to cross a sea of flame. In 

 short, that there is a belt from two to three thousand miles in breadth, 

 and reaching from one side of the ocean to the other, in which the 

 right whales are never found. Hence the discovery that the fish 

 called the right whale in the northern hemisphere is not the fish 

 which goes by this name in the southern ; that the right whale of 

 Behring's Straits and the whales of Baffin's Bay are probably the 

 game animal ; and if so, that there is at times at least an open water- 

 communication through the polar regions between the Atlantic and 

 Pacific oceans ; for this animal not being able to endure the warm 

 waters of the equator could not pass from one ocean to the other 

 unless by way of the arctic regions." 



(Rennell's Investigation of the Currents in the Atlantic Ocean; 

 Maury's Investigation of the Winds and Currents of the Sea ; Notice 

 to Mariner* ; and Chart! of the Windi and Currents of the Atlantic ; 

 Purdy's Memoir to accompany the Charts of the Atlantic Ocean, 10th 

 ed., revised by A. G. Findlay, 1853 ; Hutaboldt's Travels ; Cosmos, 

 translated by Sabine : Reports of Royal and British Associations, in 

 the Athenaeum for 1852 ; Accounts, Journals, &o., of Voyages in the 

 A rctic Regions, by Scoresby, Ross, Parry, Weddell, Back, Richardson, 

 Sutherland &c. ; Wilkin's United States Exploring Ej-pedition ; Nar- 

 rative of the Surveying Voyage of the Adrenture and Beagle ; Darwin's 

 Journal . Physical A tlaset of Berghaus, Johnston, and Petermann.) 



ATLAS is the historical and geographical name of an extensive 

 mountain system, which covers with its ranges, branches, and table- 

 lands the north-western part of Africa. Its southern boundary lies 

 between 27 and 32" N. lat., from south of Cape Nun on the Atlantic 

 Ocean to the Gulf of Cabes, or the Lesser Syrtis, opposite the island 

 of Jerbi ; the northern is formed by the southern coast of the Medi- 

 terranean Sea between Cape Spartel at the Strait of Gibraltar and 

 Cpe Bou, lying east-north-east of the town of Tunis. The coast formed 

 by its offsets and terraces along the Atlantic Ocean extends upwards 

 of 600 geographical miles, and is partly low and sandy, and partly rocky, 



oicx>. DIV. vor,. r. 



ATLAS. CS3 



but does not rise to a great height, except at Cape Ghir and a few 

 isolated places of small extent. The coast along the Mediterranean 

 between Cape Spartel and Cape Bou is generally rocky and high ; in 

 many places the elevation is very great, and it continues for a con- 

 siderable extent. Between Cape Bon and the Gulf of Cabes it is 

 likewise generally rocky to Cape Vada, but it does not rise here to a 

 great height, and is in many places interrupted by a flat sandy shore. 

 From Cape Vada to the island of Jerbi, along the Lesser Syrtis, it is 

 extremely low and sandy. 



The southern boundary of the Atlas is formed by the Great African 

 Desert, or the Sahara ; from which, as far as we know, it is separated 

 by low sandy hills, which have been blown up by the winds, and 

 which gradually encroach upon the gentle declivities with which the 

 mountains terminate on this side. On the west of the Gulf of Cabes 

 the Nofusa Mountains, which are the last offset of the Atlas toward 

 the east, are connected with the Ghuriano Moimtains, which extend 

 toward the south-east, through the kingdom of Tripoli, but for good 

 reasons are considered as not belonging to the system of the Atlas 

 Mountains. 



Within the boundary here assigned to these mountains is compre- 

 hended the whole of the empire of Fez and Marocco, and the French 

 territory of AlgeVie, as well as the greatest part of the regency of 

 Tunis. The area of these countries may amount to upwards of 

 500,000 square miles, in which case the Atlas system would cover a 

 space not much inferior to France, Germany, and Italy, taken together. 

 This vast extent of country however does not consist entirely of 

 mountain ranges and valleys, but a considerable part of it forms level 

 plains, which especially towards the shores of the Atlantic arc very 

 large ; and even between the mountain ranges along the Mediterranean 

 there are many plains. 



The principal chain, by which we mean to indicate the highest 

 ranges of the whole system, does not run parallel to the whole moun- 

 tain region from west to east, but forms rather an irregular and 

 winding diagonal, whose principal direction lies from west south-west 

 to east-north-east. It begins on the shores of the Atlantic Ocean 

 with Cape Ghir, 30 35' N. lat., which rises nearly perpendicularly 

 out of the sea to a great elevation, and extends nearly due eastward 

 to the meridian of the city of Marocco, where it turns to the east- 

 north-east, in which direction it continues to the sources of four 

 large rivers, the Wad Oom-erbegh (Morbeya), Malui'a or Maluvia 

 (the ancient Molochath or Mulucha), Ziz, or Tafilet, and Draha 

 (Draa). At this place there seems to exist an extensive mountain- 

 knot, which contains as far as we know the highest summits of the 

 whole system. These summits, which are always covered with snow, 

 are estimated by All Bey to rise 13,200 feet above the sea, but 

 Graberg of Hemsoe thinks that Mount Hentet attains the highest 

 elevation, being upwards of 15,000 feet. The highest range stretches 

 hence nearly due north, but soon declines somewhat to the east, in 

 which direction it approaches the Mediterranean. But though an 

 offset terminates with the Ras-ud-Dir, or Cabo de Tres Forcas, near 

 Melilla, it is not the principal chain ; for this, at a considerable 

 distance from the sea, seems to decline to the east, and to traverse 

 the almost unknown region designated by the name of the Desert of 

 Angad, through which the boundary-line between the empire of 

 Marocco and Algiers passes. The chain up to this point is called by the 

 Europeans the Greater Atlas ; by the natives, Daran, or Jebel Tedla 

 (Adtla). The principal chain again appears in the territory of Algiers, 

 where the highest part bears the name of Wan-nash-riz, and termi- 

 nates on the banks of the Shellif, the valley of which river probably 

 interrupts the continuity of the range. To the east of it however it 

 rises again, and forms, south-east of the town of Algiers, the high 

 summits of the Jurjura Mountains. Up to this point the range runs 

 nearly parallel with the sea-coast, at a distance of from 30 to 40 miles. 

 But hence'it declines somewhat to the south-east, and takes the names 

 of Mountains of Wannougah and of I-aite. Farther to the cast, at 

 about 8 E. long., it is called the Aturess Mountains ; and here it 

 begins to 'approach the coast again, entering under the name of the 

 Mountains of Tipara, or Tiffash, the territory of Tunis ; it terminates 

 with Cape Blanco and Cape Zibeeb, north of the town of Tunis. 



Little is known respecting the height of these mountains. One 

 summit, the Miltsin, 27 miles Sf.E. of the town of Marocco, which is 

 free from snow only once in about every twenty years, according to 

 the measurement of Lieutenant Washington, rises to 11,400 feet 

 above the level of the sea. The chains along the Mediterranean, 

 which commonly receive the general name of Lesser Atlas, are much 

 lower. Shaw states that those of Wan-nan-shcere and Jurjura are 

 the highest, and covered with snow a considerable part of the year ; 

 and the French naturalist, Desfoutes, estimated their height at 7200 

 feet. This part of the Atlas system forms the buttress of the table- 

 land or rather ten-ace of Algeria. Farther to the east the mountains 

 decrease considerably in elevation. 



We observe, with respect to the principal chain, that up to the 

 point where it enters the Desert of Angad, it forms the line of separa- 

 tion between the rivers flowing into the Atlantic Ocean and those thnt 

 run north and south into the Mediterranean Sea, or the Sahara. The 

 Lesser Atlas however docs not form Much a line of separation between 

 the water-courses running to wards different points ; the principal rivers 

 which enter the Mediterranean rise to the south of it in a lateral 



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