proportion of land to that of water is therefore nearly as one to three; or, expressing it fractionally, while one-fourth of the earth's surface is composed of dry land, the other three-fourths are covered by the waters of the ocean. Considered in hemispheres, northern and southern, the proportions of land and water are nearly as follows:

Northern Hemisphere, Land, 38,000,000 square miles.
Water, 60,500,000

Do.
Southern Hemisphere, Land, 13,500,000

do.

Do.

do.

Water, 85,000,000

There is thus about three times as much land in the northern as there is in the southern hemisphere; and if we make the estimate in eastern and western hemispheres (20° W. long. to 160° E. long.), there are about 37 millions square miles in the former, while there are only 14 millions in the latter. As to the distribution of land and water in the different zones, it may be stated, in very general terms, that the land forms about one-third of the north frigid zone; one-half of the north temperate zone; one-half of the torrid zone; one-tenth of the south temperate zone-the amount in the south frigid zone being at present unknown. The mean elevation above the sea-level of all the land on the globe-islands as well as continents, mountains as well as plains-is estimated by Humboldt at somewhat less than 1000 feet. The mean depth of the ocean is calculated by Laplace, from the tides and other phenomena, to be at least 21,000 feet. "Hence," says Sir H. Holland, "allowing full margin for errors, the entire submergence of the land might take place, leaving the solid mass of the earth everywhere deeply covered with waters, an elliptical globe of ocean, moving still under the influence of those sublime laws which had before guided its path through surrounding space."

36. The boundaries of this terraqueous arrangement (Lat. terra, land; aqua, water) are extremely irregular. Here the land spreads out in broad unbroken masses, there the waters stretch away in vast continuous expanses; here the land rises up in mere specks and fragments, there the water inserts itself among them in areas equally limited and irregular. Here the land juts boldly out into the ocean, there the ocean runs sharply into the land; here the land trends uninterruptedly for leagues, there the ocean embays itself with gentle curves into the bosom of the land. Although this distribution seems to obey no regular order, and has been continually changing throughout all geological time, yet we may rest assured -and not the less assured because we are unable to discover itthat there is a law governing the insensibly varying relations of

sea and land, a power protecting the barriers of the one, and defining the "hither shalt thou come, but no farther," of the other. This boundary between the land and water is known as the shoreline or coast-line the former having more especial reference to the margin washed by the waves, the latter to the terrestrial verge that opposes the ocean. The space alternately covered and laid bare by the tides is termed the beach or strand; and the fringe of land bordering on, and more or less influenced by, its proximity to the sea, is spoken of as the seaboard of a country or continent. This sea-belt is generally marked by the peculiarity of its plants and animals, as well as by the character of its inhabitants—these differing in many points from those of the interior or inland districts. In like manner, on the configuration of the shore-line depends much that relates to the climate as well as to the industry and commerce of a country. A regular and unbroken coast is generally an exposed and ungenial one, and one unfavourable to maritime enterprise; while one indented with gulfs and creeks and bays has more of genial diversity, and is better fitted for the purposes of navigation and commerce. As a general rule, the greater the number of miles of coast-line in proportion to the size of a country, the more valuable is that country for the requirements of industry and enterprise; and one has only to glance at the shore-lines of Europe, as compared with those of Africa or South America, to be convinced of this reality. The actions and reactions of the physical world are not more marked and certain than the influence of the physical on the intellectual and industrial; and but for the establishment of such deductions, geography would be shorn of half its interest and instruction.

37. A glance at the Map of the World will show that the landmasses are situated chiefly in the northern hemisphere-there being about three times as much land in the northern as there is in the southern hemisphere. And if we look at the distribution of this land as regards the zones of temperature, we will find that the greatest proportion is situated in the north temperate zone, or in that which contains all the better portions of Europe, Asia, and North America; while only comparatively narrow or isolated tracts are cut directly by the equator or central torrid line. Another glance at the map will show that while the land lies in broad unbroken masses towards the north, it stretches towards the south in curious gradually-tapering projections. Again, if we suppose the globe to be divided into hemispheres by the plane of the horizon of London (the dividing line being 90° all round from London), we will find that nearly all the land lies in the one hemisphere, while the other is almost wholly occupied by the

waters of the ocean. The former (see illustration) is spoken of by geographers as the Continental or Land hemisphere, while the

other is termed the Oceanic or Water hemisphere. These and other noticeable facts connected with the arrangement of sea and land have been often adverted to by writers on geography; and though it must be confessed that many of their comparisons are more curious than suggestive, there can be no doubt that the present arrangement is the result of some great cosmical law-a law concerning the nature of which neither geology nor geography can give any certain indication. This much, however, geology has shown, that the present terraqueous arrangement is not the arrangement that obtained in former ages, and that continents existed where seas now roll, and seas extended where continents are now established. We can readily account for the minor modifications of coast-lines-why some portions, composed of hard enduring rocks, should stand out in bold projections; while others, consisting of soft and wasting material, should be worn into bays and irregular recesses; but of the greater forces that slowly upheave some regions and as gradually submerge others, we are altogether ignorant. But while we fail to account for the present distribution of sea and land, and while we find that it is continually undergoing modifications under the operation of geological forces, we know that these changes are so silent and gradual as scarcely for ages to interfere with our ideas of geographical permanence and stability.

で

Their Subdivisions, Natural and Technical.

38. Admitting this condition of the terraqueous surface, it will be seen, on further reference to the Map, that the land is broken up into two main masses-that of the Eastern hemisphere, embracing Europe, Asia, and Africa, and described, from its being the only portion known to the ancients, as the Old World-and that of the Western hemisphere, including North and South America, and known (from its comparatively recent discovery by Columbus in 1492) as the New World. Properly speaking, there are only two great continuous land-masses or continents (Lat. con and tenens, holding together)—that of the Old World and that of the New; but geographers usually speak of six continents or principal sections, -viz., those of Europe, Asia, Africa, North America, South America, and Australia. Australia and its contiguous islands, together with those of the Southern Ocean, are frequently grouped as the sixth great division, under the title of Oceania; while others, drawing more restricted lines, speak of Australia and New Zealand as Australasia, and of the many islands of the Pacific proper as Polynesia. The areas of the respective continents, or quarters, as they are sometimes termed (though the "four quarters" of our forefathers embraced only Europe, Asia, Africa, and America), have been computed, with their respective islands, as follows:—

39. The islands included in the above estimate are more or less closely connected with the continents to which they belong, though in truth the continents themselves are merely islands on a much

* The subdivisions Australasia or Southern Asia (australis, southern) and Polynesia, or many islands (polys, many; nesos, island), are sufficient for our present purpose; but the student may as well understand that many geographers and ethnographers speak of the East Indian Archipelago as Malaysia; of Australia, Papua, New Zealand, and the minor contiguous islands as Australasia or Melanesia (melas, black), in reference to the colour of their aboriginal population; of the numerous small Pacific islands north of the equator and east of Malaysia as Micronesia (micros, small); and of the many groups lying south of the equator and east of Australasia as Polynesia.