old Ocean as a Builder 



places has undoubtedly risen and sunk, the ocean- 

 surface may have risen and sunk also. 



The ocean could not, indeed, like the land have 

 risen or sunk only in parts. Except where it is 

 forcibly held at a higher level by some strong 

 force of local attraction, this would be impossible. 

 Yet causes might exist which should affect the 

 whole ocean-surface. 



One such may be mentioned. The rising or 

 sinking of great tracts of land could not fail to 

 affect the ocean-level. 



That it must do so may be easily understood. 

 Let us fill a basin with water, to within an inch 

 of the brim, and then slowly lower into the water 

 a ball, or any other solid body. As the ball 

 enters, the level of the water rises — must rise. 

 Then let us slowly lift the ball out again ; and as 

 it leaves the water, the level of the latter sinks — 

 must sink. 



Precisely the same result would follow upon 

 the risino^ or sinkinor of some orreat continental 

 mass. When it rises, the ocean contains less 

 land, and the water-level must go down. When 

 it sinks, the ocean contains more land, and the 

 water-level must go up. 



This question has been long under discussion. 

 For many years, as with other questions, each 



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