10 THE OCEAN WOKLD. 



seven thousand and forty fathoms, but without bringing up any soil from 

 the bottom. Among the fragments brought up from the bottom of the 

 Coral Sea, a remarkable absence of calcareous shells was noted, whilst 

 the siliceous fragments of sponges were found in great quantities. Other 

 soundings made in the Pacific, at a depth of four or five miles, were 

 examined by Ehrenberg, who found a hundred and thirty-five different 

 forms of infusoria represented, and among them twenty-two species new 

 to him. Generally speaking, the composition of the infusoria of the 

 Atlantic are calcareous; those of the Pacific, siliceous. These ani- 

 malcules draw from the sea the mineral matter with which it is 

 charged that is, the lime or silica which form their shell. These 

 shells accumulate after the death of the animal, and form the bottom 

 of the ocean. The animals construct their habitations near the surface ; 

 when they die, they fall into the depths of the ocean, where they 

 accumulate in myriads, forming mountains and plains in mid ocean. 

 In this manner, we may remark, en passant, many of the existing con- 

 tinents had their birth in geological times. The horizontal beds of 

 marine deposits, which are called sedimentary rocks, and especially 

 the cretaceous rocks and calcareous beds of the Jurassic and Tertiary 

 periods, all result from such remains.* 



The sea level is, in general, the same everywhere. It represents 

 the spherical form of our planet, and is the basis for calculating all ter- 

 restrial heights ; but many gulfs and inland seas open on the east are 

 supposed to be exceptions to this rule : the accumulation of waters, 

 pressed into these receptacles by the general movement of the sea 

 from east to west, it is alleged, may pile up the waters, in some 

 cases, to a greater height than the general level. 



It had long been admitted, on the faith of inexact observation, that 

 the level of the Bed Sea was higher than that of the Mediterranean, 

 It has also been said that the level of the Pacific Ocean at Panama is 

 higher by about forty inches than the mean level of the Atlantic at 

 Chagres, and that, at the moment of high water, this difference is 

 increased to about thirteen feet, while at low it is over six feet in the 

 opposite direction. This has been proved, so far as the evidence goes, 

 to be error in what concerns the difference in level of the Bed Sea and 

 Mediterranean; and the opening of the Suez Canal, which is near at 

 hand, will probably furnish still more convincing proofs. Becent 



* "World before the Deluge." Second edition. 



