THE EARTH. 24-7 



of earth which forms its bottom. It iq at the 

 bottom of the sea that the greatest wonders are 

 performed, and the most rapid changes are pro- 

 duced ; it is there that the motion of. the tides 

 and the currents have their whole force, and 

 agitate the substances of which their bed is com- 

 posed. But all these are almost wholly hid from 

 human curiosity; the miracles of the deep are 

 performed in secret; and we have but little in- 

 formation from its abysses, except what we re- 

 ceive by inspection at very shallow depths, or 

 by the plummet, or from divers, who are knpwn 

 to descend from twenty to thirty fathoms. * 



The eye can reach but a very short way into, 

 the depths of the sea; and that only when its 

 surface is glassy and serene, In many seas it 

 perceives nothing but a bright sandy plain a 

 bottom, extending fi?r several hundred TOilss, 

 without an intervening object. But foi others, 

 particularly in the Red Sea, it is very different ; 

 the whole bottom of this extensive bed of wafers 

 is, literally speaking, a forest of sub-marine} plants, 

 and corals formed by insects for their habitation, 

 sometimes branching PUt to a great extent. Here 

 are seen the madrepores, the sponges, mosses, 

 sea mushrooms, and other marine productions, 

 covering every part of the bottom ; so that some 

 have even supposed the sea to have tafeen its 

 name from the colour of its plants below- How- 

 ever, these plants are by no means peculiar to 

 this sea, as they are found ^ re & quantities 



Phil. Trans, vol. IT. part ii. p. 192. 



