PHYSICAL GEOGRAPHY. 



the habitat of the most advanced races. The fol- 

 lowing table exhibits the number of square miles 

 of area to one mile of coast in the several large 

 divisions of land, thus affording a measure of the 

 comparative accessibility of the interior : 



Europe 157 sq. miles of area to i mile of coatt. 



Asia 528 



Africa 738 



North America 266 



South America. 440 



Australia 340 



The insular portions of the globe are not less 

 worthy of notice than the continents themselves. 

 We find them sometimes solitary, oftener collected 

 into groups or archipelagoes ; in some cases they 

 are little more than low sand-banks, ledges of 

 rocks, or coral reefs ; and in others rising to a 

 considerable elevation above the surface of the 

 water, and spreading to a considerable extent 

 they present in miniature all the features of the 

 continents to which they belong. They are often 

 the summits of submarine mountain-chains, and, 

 as such, are intimately connected with each other 

 and with the neighbouring mainland. Many of 

 them are evidently the production of volcanic forces 

 the dawn of new continents emerging from the 

 waters, as others are the gradually submerging relics 

 of former terrestrial regions. The most important 

 island-groups are the British, Japan, Philippine, 

 and East Indian in the eastern hemisphere ; and 

 the West Indian and Polynesian in the western. 

 The largest individual islands (regarding Australia 

 as a continent) are Borneo, with an area of about 

 280,000 square miles ; Madagascar, 234,000 ; New 

 Guinea, whose outline is yet imperfectly known ; 

 Sumatra, 177,000; Niphon, 109,000; Great Bri- 

 tain, 90,000 ; Nova Zembla, 25,000 ; Newfound- 

 land, 40,000; Cuba, 43,400; and Iceland, 40,000 

 square miles. 



Islands, we have said, are either connected with 

 existing continents, are portions of former conti- 

 nents now submerged, or are new and independent 

 elevations. Thus, if an island is of the same 

 geological formation with the adjoining mainland, 

 we must regard it either as a portion separated by 

 depression, or as a belated portion only rising into 

 dry land. In either case, we are bound to con- 

 sider it in all its relations vital as well as physical 

 as belonging to the adjacent continent. Again, 

 islands of totally different formation from that of 

 the nearest continent may in most cases be re- 

 garded either as relics of former lands, or as new 

 lands rising into day ; and we are not to be startled 

 at the fact of their exhibiting like Australia 

 races of plants and animals altogether peculiar. 



Such is a brief glance at the partition of the dry 

 land (so far as it is known) into continents and 

 islands a partition which exercises an all-import- 

 ant influence over organic existence, and which, 

 after all, is dependent on very minute geological 

 operations. A general elevation of the solid crust 

 in the eastern hemisphere, for example, would 

 connect Britain with the continent of Europe, the 

 Lofoden Islands with the Scandinavian peninsula, 

 enlarge the connection between Asia and Africa, 

 elevate the Sunderbunds of the Ganges into a vast 

 plain, the Laccadive and Maldive reefs into exten- 

 sive islands, and the bed of the Yellow Sea into an 

 alluvial plain. Equally important results depend 

 upon the relative positions of the continents and 

 islands. Had South America, unaltered in a 



single square yard, lain parallel with, instead of 

 crossing, the equator, or had Africa been inter- 

 sected by seas, as Europe is, it requires no stretch 

 of imagination to conceive the radical difference 

 which their Flora and Fauna would have pre- 

 sented. As regards man, and the highest aim 

 of creation the civilisation of man the present 

 arrangement is of the first importance. The theatre 

 of his operations all arctic, and he would never 

 have risen above the condition of the Laplander 

 or Esquimaux ; all antarctic, and behold his con- 

 dition in that of the miserable Fuegian ; all tropi- 

 cal, and see him in a state of languid, enervated, 

 semi-civilisation ; while balanced as conditions 

 are, see his progress mainly in one broad zone, 

 where Chinese, Indian, Persian, Chaldean, Syrian, 

 Egyptian, Greek, Roman, Frank, and Anglo-Saxon 

 have successively or simultaneously figured in the 

 march of improvement 



MOUNTAINS AND TABLE-LANDS. 



As elevation above the waters of the ocean is 

 the origin of the dry land, so its most prominent 

 features are those peculiar upheavals known by the 

 name of hills and mountains. The theory of their 

 upheaval belongs to Geology ; but according to 

 their character, so is that of the regions to which 

 they belong, generally speaking, determined. They 

 subserve numerous and important purposes in 

 nature. Rising into regions of perpetual ice, they 

 serve, in hot climates, to temper the air with the 

 breezes generated around their heights ; they are 

 the reservoirs of rivers, supplying the shrinking 

 streams, in the dry seasons of the lower countries, 

 with copious torrents from their melting snows ; 

 they are in most instances the storehouses of the 

 richest minerals ; they increase and diversify the 

 surface of the earth ; and, by presenting impassable 

 barriers between opposite regions, they give variety 

 and richness to animal and vegetable life : we say 

 impassable barriers, for the broadest seas are not 

 half so effective in obstructing the dispersion of 

 vegetable and animal life as lofty snow-clad 

 mountains. 



Isolated mountains of great height are of rare 

 occurrence, and when they do appear, are usually 

 active or recent volcanoes. Hills and mountains, 

 whether rising to the height of 1000 or 20,000 feet, 

 generally appear in chains or ranges, consisting 

 either of one central chain, with branches running 

 off at right angles, or of several chains or ridges 

 running parallel to each other ; and in both cases 

 often accompanied by subordinate chains of minor 

 elevation. Several chains constitute what is called 

 a group; and several groups, a system. The 

 relative ages of mountain-chains appertain more 

 especially to the province of the geologist ; but 

 with their epochs is connected their physiognomy 

 or contour, a subject eminently interesting to 

 the geographer. So persistent is the contour of 

 mountains, whether associated with the older or 

 more recent formations, that the practised eye of 

 the geologist can generally determine at a glance 

 the era of their upheaval The bold, but bald and 

 massive heights of a granitic mountain differ widely 

 in aspect from the abrupt and splintery crags 

 and pinnacles of the older stratified formations ; 

 while the rounded, undulating, and terraced out- 

 line of the secondary trap-hills distinguishes them 

 at once from the conical crateriform heights of the 



