LIFE OF JAMES DWIGHT DANA 



been made about the heights of a single subsiding land 

 of large size. Such facts show additional error in the 

 above estimate, evincing that the scattered atolls and 

 reefs tell but a small part of the story. Why is it, also, 

 that the Pacific islands are confined to the tropics, if not 

 that beyond thirty degrees the zoophyte could not plant 

 its growing registers ? " 



Although some repetition will follow, I think that 

 readers generally will enjoy the perusal of a popular ad- 

 dress on coral formations, which was given to a private 

 circle in New Haven, February 19, 1855, by the naturalist, 

 then fresh from his prolonged study of the zoophytes. 



A PARLOR LECTURE ON CORALS BY PROFESSOR DANA 



" By suggestion from one whom we all hold in high 

 esteem, I have been led to select for brief remark this 

 evening the subject of Coral Formations. 



" The coral atoll is well described as a monument 

 erected over a buried island. I propose to show how this 

 seeming extravagance of poetry is actually sober scientific 

 fact. A description of the appearance of the coral atoll 

 above and beneath the water, and its growth amid the 

 waves, will prepare the way for the real poetry of science, 

 which, in opposition to one who has sung of coral islands, 

 I believe to be found in the truth. 



" The atoll so called from the language of the Mal- 

 dives consists of a narrow rim of coral reef, a few hun- 

 dred yards wide, surrounding a lake or lagoon. It lies 

 in mid-ocean, just emerging above the surface, a coral 

 garden beneath the waters, a circling grove of palms 

 above. The land is raised but ten feet above the tides, 

 or eighty to one hundred feet to the tops of the palms or 

 cocoanut trees. A vessel approaches almost within hail 

 before the atoll is fairly in sight. At first, there is seen 

 a range of dots low in the distant horizon. As the ship 

 speeds on, these dots expand into the plumed tops of 

 cocoanut palms. Then the deep green grove springs into 

 full view, with the dazzling white beach in front so 

 white and shadowless that it seems like a vertical wall ; 

 while the heavy breakers are careering and foaming along 



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