Chili, Buenos Ayres, the southern part of Brazil, and Peru, enjoy the cool summers and mild winters of a true insular climate, owing to the narrowness and contraction of the continent towards the south. This advantage of the Southern Hemisphere is manifested as far as 48° or 50° south lat., but beyond that point, and nearer the Antarctic Pole, South America is an inhospitable waste. The different degrees of latitude at which the southern extremities of Australia, including Van Diemen’s Island, of Africa, and America, terminate, give to each of these continents its peculiar character. The Straits of Magellan lie between the parallels of 53° and 54° south lat.; and notwithstanding this, the thermometer falls to 41° Fahr. in the months of December and January, when the sun is eighteen hours above the horizon. Snow falls almost daily in the lowlands, and the maximum of atmospheric heat observed by Churruca in 1788, during the month of December, and consequently in the summer of that region, did not exceed 52°.2 Fahr. The Cabo Pilar, whose turret-like rock is only 1394 feet in height, and which forms the southern extremity of the chain of the Andes, is situated in nearly the same latitude as Berlin.[[EH]]
Whilst in the Northern Hemisphere all continents fall, in their prolongation towards the Pole, within a mean limit, which corresponds tolerably accurately with 70°, the southern extremities of America. (in Tierra del Fuego, which is so deeply indented by intersecting arms of the sea,) of Australia, and of Africa, are respectively 34°, 46° 30′ and 56° distant from the South Pole. The temperature of the unequal extents of ocean which separate these southern extremities from the icy Pole contributes essentially towards the modification of the climate. The areas of the dry land of the two hemispheres separated by the equator are as 3 to 1. But this deficiency of continental masses in the Southern Hemisphere is greater in the temperate than in the torrid zone, the ratio being in the former at 13 to 1, and in the latter as 5 to 4. This great inequality in the distribution of dry land exerts a perceptible influence on the strength of the ascending atmospheric current, which turns towards the South Pole, and on the temperature of the Southern Hemisphere generally. Some of the noblest forms of tropical vegetation, as for instance tree-ferns, advance south of the equator to the parallels of from 46° to 53°, whilst to the north of the equator they do not occur beyond the tropic of Cancer.[[EI]] Tree-ferns thrive admirably well at Hobart Town in Van Diemen’s Land (42° 53′ lat.), with a mean annual temperature of 52°.2 Fahr., and therefore on an isothermal line less by 3°.6 Fahr. than that of Toulon. Rome, which is almost one degree of latitude further from the equator than Hobart Town, has an annual temperature of 59°.7 Fahr.; a winter temperature of 46°.6 Fahr., and a summer temperature of 86° Fahr.; whilst in Hobart Town these three means are respectively 52°, 42°.1, and 63° Fahr. In Dusky Bay, New Zealand, tree-ferns thrive in 46° 8′ lat., and in the Auckland and Campbell Islands in 53° lat.[[EJ]]
In the Archipelago of Tierra del Fuego, having a mean winter temperature of 33° Fahr., and a mean summer temperature of only 50° Fahr., in the same latitude as Dublin, Captain King found “vegetation thriving most luxuriantly in large woody-stemmed trees of Fuchsia and Veronica;” whilst this vigorous vegetation, which, especially on the western coast of America (in 38° and 40° south lat.), has been so picturesquely described by Charles Darwin, suddenly disappears south of Cape Horn, on the rocks of the Southern Orkney and Shetland Islands, and of the Sandwich Archipelago. These islands, but scantily covered with grass, moss, and lichens, Terres de Désolation, as they have been called by French navigators, lie far to the north of the Antarctic Polar Circle; whilst in the Northern Hemisphere, in 70° lat., on the extremest verge of Scandinavia, fir-trees reach a height of more than 60 feet.[[EK]] If we compare Tierra del Fuego, and more particularly Port Famine, in the Straits of Magellan, 53° 38′ lat., with Berlin, which is situated one degree nearer the equator, we shall find for Berlin, 47°.3 38°.9
62°.3; and for Port Famine, 42°.6 34°.7
50°.0 Fahr. I subjoin the few certain data of temperature which we at present possess of the temperate zones of the Southern Hemisphere, and which may be compared with the temperatures of northern regions in which the distribution of summer heat and winter cold is so unequal. I make use of the convenient mode of notation already explained in which the number standing before the fraction indicates the mean annual temperature, the numerator the winter, and the denominator the summer temperature.
| Places. | South Latitude. | Mean Annual, Winter, and Summer Temperatures. | |
|---|---|---|---|
| 54°.5 | |||
| Sydney and Paramatta (New Holland) | 33° 50′ | 64°.6 | |
| 77°.5 | |||
| 58°.5 | |||
| Cape Town (Africa). | 33° 55′ | 65°.7 | |
| 73°.2 | |||
| 52°.5 | |||
| Buenos Ayres | 34° 17′ | 62°.4 | |
| 73°.0 | |||
| 57°.4 | |||
| Monte Video | 34° 54′ | 67° | |
| 77°.5 | |||
| 42°.1 | |||
| Hobart Town (Van Diemen’s Land) | 42° 45′ | 52°.5 | |
| 63°.0 | |||
| 34°.7 | |||
| Port Famine (Straits of Magellan) | 53° 38′ | 42°.6 | |
| 50°.0 | |||
[21]. p. 9.—“One connected sea of sand.”
As we may regard the social Erica as furnishing one continuous vegetable covering spread over the earth’s surface, from the mouth of the Scheldt to the Elbe, and from the extremity of Jutland to the Harz mountains, so may we likewise trace the sea of sand continuously through Africa and Asia, from Cape Blanco to the further side of the Indus, over an extent of 5,600 miles. The sandy region mentioned by Herodotus, which the Arabs call the Desert of Sahara, and which is interrupted by oases, traverses the whole of Africa like a dried arm of the sea. The valley of the Nile is the eastern boundary of the Lybian desert. Beyond the Isthmus of Suez and the porphyritic, syenitic, and greenstone rocks of Sinai begins the Desert mountain plateau of Nedschd, which occupies the whole interior of the Arabian Peninsula, and is bounded to the west and south by the fruitful and more highly favoured coast-lands of Hedschaz and Hadhramaut. The Euphrates forms the eastern boundary of the Arabian and Syrian desert. The whole of Persia, from the Caspian Sea to the Indian Ocean, is intersected by immense tracts of sand (bejaban), among which we may reckon the soda and potash Deserts of Kerman, Seistan, Beludschistan, and Mekran. The last of these barren wastes is separated by the Indus from the Desert of Moultan.
[22]. p. 9.—“The western portion of Mount Atlas.”
The question of the position of the Atlas of the ancients has often been agitated in our own day. In making this inquiry, ancient Phœnician traditions are confounded with the statements of the Greeks and Romans regarding Mount Atlas at a less remote period. The elder Professor Ideler, who combined a profound knowledge of languages with that of astronomy and mathematics, was the first to throw light on this obscure subject; and I trust I may be pardoned if I insert the communications with which I have been favoured by this enlightened observer.
“The Phœnicians ventured at a very early period in the world’s history to penetrate beyond the Straits of Gibraltar. They founded Gades and Tartessus on the Spanish, and Lixus, together with many other cities on the Mauritanian coasts of the Atlantic Ocean. They sailed northward along these shores to the Cassiterides, from whence they obtained tin, and to the Prussian coasts where they procured amber found there; whilst southward they penetrated as far as Madeira and the Cape de Verd Islands. Amongst other regions they visited the Archipelago of the Canary Isles, where their attention was arrested by the Peak of Teneriffe, whose great height appears to be even more considerable than it actually is from the circumstance of the mountain projecting directly from the sea. Through their colonies established in Greece, especially under Cadmus in Bœotia, the Greeks were made acquainted with the existence of this mountain which soared high above the region of clouds, and with the ‘Fortunate Islands’ on which this mountain was situated, and which were adorned with fruits of all kinds, and particularly with the golden orange. By the transmission of this tradition through the songs of the bards, Homer became acquainted with these remote regions, and he speaks of an Atlas to whom all the depths of ocean are known, and who bears upon his shoulders the great columns which separate from one another the heavens and the earth,[[EL]] and of the Elysian Plains, described as a wondrously beautiful land in the west.”[[EM]] Hesiod expresses himself in a similar manner regarding Atlas, whom he represents as the neighbour of the Hesperides.[[EN]] The Elysian Plains, which he places at the western limits of the earth, he terms the ‘Islands of the Blessed.’[[EO]] Later poets have still further embellished these myths of Atlas, the Hesperides, their golden apples, and the Islands of the Blessed, which are destined to be the abode of good men after death, and have connected them with the expeditions of the Tyrian God of Commerce, Melicertes, the Hercules of the Greeks.
“The Greeks did not enter into rivalship with the Phœnicians and Carthaginians in the art of navigation until a comparatively late period. They indeed visited the shores of the Atlantic, but they never appear to have advanced very far. It is doubtful whether they had penetrated as far as the Canary Isles and the Peak of Teneriffe; but be this as it may, they were aware that Mount Atlas, which their poets had described as a very high mountain situated on the western limits of the earth, must be sought on the western coast of Africa. This too was the locality assigned to it by their later geographers Strabo, Ptolemy, and others. As however no mountain of any great elevation was to be met with in the north-west of Africa, much perplexity was entertained regarding the actual position of Mount Atlas, which was sought sometimes on the coast, sometimes in the interior of the country, and sometimes in the vicinity of the Mediterranean, or further southward. In the first century of the Christian era, when the armies of Rome had penetrated to the interior of Mauritania and Numidia, it was usual to give the name of Atlas to the mountain chain which traverses Africa from west to east in a parallel direction with the Mediterranean. Pliny and Solinus were both, however, fully aware that the description of Atlas given by the Greek and Roman poets did not apply to this mountain range, and they therefore deemed it expedient to transfer the site of Mount Atlas, which they described in picturesque terms, in accordance with poetic legends, to the terra incognita of Central Africa. The Atlas of Homer and Hesiod can, therefore, be none other than the Peak of Teneriffe, while the Atlas of Greek and Roman geographers must be sought in the north of Africa.”