54 



THE OPAL SEA 



sea and not raise its temperature more than 

 half a degree. Moreover, the area of heat- 

 gathering water is too limited to affect the 

 great body profoundly. Ninety per cent of the 



Ocean tem- 

 peratures. 



The aea 

 bedt. 



Monntaina 

 in the aea. 



ocean waters fall below 40° F. So, with all the 

 warming and tempering effect of the sea upon 

 certain climates or countries, it is still some- 

 thing of a cold blanket wrapped about the 

 earth. 



As for tlie sea beds themselves, one cannot 

 think of them as other than the bottoms of 

 wide valleys or great, flat basins lying far be- 

 low us — sunken basins of the earth where the 

 waters have lodged by force of gravital circum- 

 stance. The irregularities of the earth's sur- 

 face foot up in actual height and depth a dif- 

 ference of some ten or a dozen miles. That is 

 to say, if we consider sea level as the mean, 

 we shall find mountains rising above it five 

 or six miles and ocean troughs falling below it 

 five or six miles. But there the resemblance 

 seems to end, for there are no such abrupt 

 mountains, valleys, or precipices in the sea as 

 upon the land. 



And yet there are exceptions to such a con- 

 clusion. The island group of the Bermudas 

 is clearly a mountainous mass springing up- 

 ward from the sea floor. The upper part of it 



