500 LIFE IN THE DEEP SEA. 



earth, this will be on the scale of i foot to 200 miles, or i inch 

 to 165 miles or 88,000 feet.* Thus, on such a globe, the 

 highest mountain and the deepest sea would be on true propor- 

 tional scale represented severally by an elevation or depression 

 of one-third of an inch. Were the land surfaces and sea beds 

 sculptured in due proportion on the face of this globe, the 

 surface would at a little distance hardly appear roughened, so 

 insignificant is the altitude of the highest mountains and the 

 depth of even the deepest seas in proportion to the dimensions 

 of the earth itself. The oceans in relation to their superficial 

 area are as shallow as a sheet of water one hundred yards in 

 diameter, and only an inch in depth, f 



We are apt to form an erroneous impression as to the actual 

 shapes and distributions of the elevations and depressions on 

 the earth's surface, because only the very tops of the elevations 

 stand above water. The outlines of the various continents 

 and islands with which we are familiar on maps, are merely 

 lines marking the height to which the water reaches up. A 

 very small proportion of the elevated masses projects above 

 water, hence from an ordinary map we gain no truer impression 

 of the form of the sculpturing of the surface of the earth itself 

 than we should of the shape of a range of mountains if we 

 viewed it when all but its summits were hidden by a flood. 



So small a proportion does the mass of dry land elevated 

 above sea-level bear to the hollows on the earth's surface 

 beneath this level, that the cavities now occupied by the sea 

 would contain three times the volume of the earth existing 

 above the sea surface. If the surface of the land and the 

 sea bottom were brought to one uniform level, the waters of 

 the sea covering its even face would still have a depth of about 

 1,700 fathoms, being reduced in depth by the process only 

 about 800 fathoms. J 



We should obtain a more correct idea of what are the real 

 elevations and what the depressions on the earth's surface, if 

 we drew on the map or globe a contour line marking the level 

 at which the mass of the earth raised above this line is just 

 equal to the excavations beneath it, and would just fill up these 

 hollows if the surface of the earth were rendered even and 

 smooth. 



Although the depth of the ocean is so small in proportion to 



* Lieut.-Gen. R. Strachey, R.E., F.R.S., " Lecture on Scientific 

 Geography." Proc. Geogr. Soc, 1877, p. 191. 



f James Croll, "Climate and Time," p. 135. London, Daldy & Co., 



'875- 



+ O. Peschel, "Neue Probleme der vergleichenden Erdkunde.' Leipzig, 

 1876, s. 82. 



