(To be read before a Map.)

If the waters of the Atlantic could be drawn off, so as to expose to view the great trough which separates the Old World from the New, a scene would present itself of the grandest and most imposing character. The very ribs of the solid Earth, and the foundations of the hills, destitute of the garniture of vegetation, would be brought to light. We should have unrolled before us a vast panorama of mountains and valleys, of tablelands and plains, of deep gorges and lofty peaks, rivalling in grandeur and in variety the continents of the upper world.

Comparatively little is yet known of the bed of the South Atlantic; but the basin of the North Atlantic has been extensively surveyed by the English and American Navies. Let us suppose this vast basin to be emptied of its waters; and, with the aid of the charts which have been constructed, let us in imagination traverse these deep places of the Earth and learn what we can of their secrets. Remembering that what we have to explore is really a vast system of table-lands, mountains, and valleys, let us first endeavour to grasp its broad outstanding features.

In the northern part of the basin there stretches across the Atlantic from Newfoundland to Ireland a great submarine plain, known in recent years as Telegraph Plateau. About one hundred miles from the coast of Ireland this plateau, rising as a broad terrace, reaches to within a hundred fathoms of the surface of the ocean. On this terrace stand the British Islands, the climate of which is materially affected by their being thus removed from the influence of the colder waters in the depths of the Atlantic. About midway between these islands and Iceland, it has been found that icy cold water is constantly flowing towards the Equator, at a considerable depth beneath the surface, to supply the place of the warm surface-water moving northward from the Equator. At the depth of three-quarters of a mile, the temperature of this great polar current is two degrees below the freezing point. The British terrace raises these isles out of this cold stream, and thus none but the warmer upper waters flow around the British coasts.

From the middle of Telegraph Plateau an immense submarine continent, nearly as extensive as South America, stretches first southward and then towards the west, occupying the whole central area of the North Atlantic basin.

On either side of this central continent there is a broad and deep valley. These valleys converge as they go southward, and meet in mid-ocean between the Cape Verd and the West India Islands. Of these valleys, the western is much deeper than the eastern. Its deepest parts are found midway between the Bermudas and the Azores, and off the island of Porto Rico, where the sounding-line has been carried deeper than anywhere else in the ocean. It is the deepest part of the Atlantic.

Could we transport ourselves to that point, we should stand on what is perhaps the very lowest part of the Earth's crust. We should be at least five miles below the ordinary level of the sea, surrounded on all sides by great mountains. On the north the Bermudas would be seen as lofty mountain-peaks, rising half as high again as the summits of the Alps or the Andes. On the north-east we should see the Azores as the culminating points of the central continent. Pico, their highest point, would appear, from the general level, as a mountain 400 feet higher than Mont Blanc; but from our imaginary standpoint in the lowest depths of the Atlantic, it would be six and a half miles in height — a mile higher than the highest peak of the Himalaya, the loftiest mountain on the globe.

Each of these great ocean valleys rises in a series of terraces to the sides of the Old and New Worlds respectively. The course of the western valley, which lies off the United States and the West India Islands, has been traced as far south as to the Equator. The terraces of the eastern valley rise from the depths of the ocean to the western coasts of Europe and Africa. Off the coast of Africa they rise into a series of lofty and rugged summits, which we call Madeira, the Cape Verd, and the Canary Isles; and the whole system culminates in the Peak of Teneriffe in the last-named group. That peak is two miles and one-third above the level of the sea. The lowest point yet sounded in the bed of the Atlantic is five miles and a third below that level. The whole mountain system of the Atlantic basin, therefore, extends to upwards of seven miles in vertical height, or higher than any of the mountains of the globe are above the level of the sea.

By bringing up specimens from the depth of the Atlantic, and studying them under the microscope, it has been ascertained that the bed of the ocean is covered with very minute shells, which lie on the bottom as lightly as gossamer. The microscope has not detected a single particle of sand or gravel among these little mites of shells. This fact proves that quiet reigns in the depths of the sea: that as in the air ocean there is a region of perpetual calm, “above the clouds;” so in the ocean of waters there is a region where perpetual calm prevails, beneath the troubled waves. There is not motion enough to abrade these very delicate organisms, nor current enough to sweep them about, or to mix with them a grain of the finest sand.

It may be that the myriads of animalcules which make the sea glow with life are secreting from it solid matter which is destined to fill up the cavities below. They furnish the atoms of which mountains are formed and plains are spread out. Our marl-beds, the clay in our river-bottoms, large portions of many of the great basins of the Earth, even flinty rocks, are composed of the remains of just such minute animals as those which have been fished up from a depth of three miles below the sea-level. These creatures, therefore, when living, may have been preparing the ingredients for the fruitful soil of a land that some earthquake or upheaval, in ages far away in the future, may yet raise up from the bottom of the sea for the use of man.

Words

ascertained,found.

cavities,hollow places.

converge,draw near to each other.

culminating,crowning.

destined,appointed.

detected,discovered.

garniture,embellishment.

gossamer,cobweb.

ingredients,elements.

organisms,structures.

panorama,comprehensive view.

perpetual,constant.

separates,keeps apart.

submarine,under the sea.

summits,peaks.

surveyed,examined.

temperature,degree of heat.

transport,convey.

Questions

Of what does the bed of the ocean consist? What part of the Atlantic has been surveyed? By whom? What plain stretches across the northern part of the basin? On what do the British Isles stand? What effect has this on their climate? Why? What extends southward from the middle of Telegraph Plateau? What is there on either side of the central continent? Where is the deepest part of the Atlantic? If we could stand there, how far should we be below the sea-level? By what should we be surrounded? What would the Bermudas appear to be? And the Azores? Where does the whole Atlantic mountain system culminate? What is its extent in vertical height? With what is the bed of the ocean covered? What shows that quiet reigns in the depths of the sea? Of what are the animalcules found in the bed of the ocean the elements?

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如果大西洋的水可以被抽干，來顯現(xiàn)出分隔開新世界與舊世界的一條巨大海槽，一幅宏偉壯觀的景象會展現(xiàn)在我們面前。堅硬地球的山脊，山脈的形成，植被裝飾的貧乏，會被一一發(fā)現(xiàn)。在我們面前展現(xiàn)出的是一幅巨大的關(guān)于山脈和山谷、高原和平原、深邃峽谷和巍峨山峰的全景，競相展現(xiàn)著它們的宏偉和上層世界的多樣性。

相比之下，人們對南大西洋的海床知之甚少。但英國和美國海軍已經(jīng)對北大西洋盆地進行了廣泛勘測。我們可以假設(shè)這片廣闊的盆地沒有水，在已經(jīng)構(gòu)制的航海圖的幫助下，我們的想象可以穿越這片地球上最深的海域，去了解我們可以得知的秘密。須謹記我們要探索的的確是一片廣闊的高原、山脈和山谷，我們首先可以嘗試的是，掌握它們眾多的顯著特征。

在這片盆地的北部區(qū)域，橫跨大西洋，從紐芬蘭島到愛爾蘭島，綿延著一片寬廣的海底盆地，近年來被稱作“電報高原”。在距愛爾蘭海岸大約100英里處，這片高原如一片寬廣的梯田升起，一直到達距海面不足100英寸之內(nèi)。不列顛群島矗立其上，而不列顛群島的氣候深受這些梯田的影響，而免受大西洋底部冰冷海水的影響。大約在這些島嶼和冰島的正中，人們發(fā)現(xiàn)寒冷的冰水在海面以下極深的深度，不停地向北流向赤道，供給這片區(qū)域溫暖的海面水，向北部的赤道流淌。在大約四分之三英里的深度，水的溫度低于冰點兩度。不列顛梯田因為寒流升高影響到這些小島，以致只有這種溫暖的上層水流圍繞不列顛海岸流淌。

一片幾乎和南美洲一樣廣闊的巨大的海底陸地，從電報高原的中央首先向南延伸，之后向西，占據(jù)了北大西洋盆地的整個中心地區(qū)。

在中央陸地的周圍，有寬廣且深邃的山谷，它們向南部延伸時同時匯聚集，在佛得角和西印度群島中央處聚于一處。這些山谷的東部比西部深得多。它最深的地方位于百慕大和亞速爾群島之間，而在波多黎各島的外圍，攀升至比海洋中其他任何地方都更深的部位，這就是大西洋最深的地方。

如果我們能夠到達這一點，我們即將位于地殼最低點，也就是在平均海洋高度下至少5英里處，且四周都包圍著高山。在北部，百慕大是一片巍峨的山峰，高至如阿爾卑斯和安第斯山制高點一半的高度。在東北部，我們會看到亞速爾群島是整個中央陸地的最高點。從海洋的一般高度出發(fā)，最高點皮科，相當于比勃朗峰還要高400英寸的山。而從我們想象中的站立點出發(fā)，在大西洋的最深處，它會有6.5英里高。這比全球最巍峨的山峰——喜馬拉雅山的最高峰——還要高出一英里。

這些廣闊的海洋山谷都沿梯田狀分別攀升至新舊世界的邊緣。西部山谷的攀升軌跡沿著美國和西印度群島的外圍，一直向南延伸至赤道。東部山谷的梯田從海底攀升，一直到歐洲和非洲的西海岸。在非洲海岸邊緣，它們形成了巍峨崎嶇的制高點，也就是馬德拉、佛得角和加那利群島。而這整個一片山谷達到特內(nèi)里費峰這一最高點時，位于海平面的英里之上。而大西洋海床的最低點，在海平面之下英里處。因此大西洋盆地的整個山區(qū)在垂直高度向上延伸了7英里。或者可以說，這比地球上海平面之上的所有山峰都要高。

通過從大西洋底部采取的樣本，并在顯微鏡下對它們進行的研究，我們能確定大西洋海床遍布了微小的貝殼。它們像游絲一樣微小，停留在海洋底部。顯微鏡沒有在這些貝殼中發(fā)現(xiàn)任何顆粒物或者礫石。由此可以得知，寧靜統(tǒng)治了整個海洋底部，這里是一片如云端之上由寧靜統(tǒng)治的區(qū)域。海水中，在洶涌的波濤之下，四處都籠罩著這種永久的寧靜。沒有任何動態(tài)能夠腐蝕這些微妙的微生物，也沒有任何波濤讓它們隨波逐流，或者任何細沙能夠?qū)⑺鼈兓祀s。

也許正是這無數(shù)的微生物使海洋變得生機盎然，而它們隱匿于那些注定要充斥著海底空洞的堅硬物質(zhì)。它們提供了構(gòu)成山脈和延展平原的原子。正是這些在海平面之下3英里處可以找到的微生物，構(gòu)成了我們海床的泥灰，河流的黏土，還有地球廣闊盆地的絕大份額，甚至是堅硬的巖石。因此當這些生物還有生命時，就已經(jīng)做好了準備成為地球肥沃土壤的成分，在將來的許多年之后，甚至會引發(fā)地震或者地殼隆起。也正是它們，可能會從海洋底部升起，為人類所用。