To Charles Lyell [24 January 1847]
My dear Lyell
I do not understand Mr Gould;1 the reef under water, I suppose is the “flat” of dead rock, often partically covered with water, separating the living margin of reef, from the islets, which Dr. Gould calls the Barrier.— I often refer to & have described it.— Tahiti is much less perfectly encircled than any other island of that group, but I consider it is encircled from Cooks chart,2 which has been copied into all the French Voyagers, who had some means of knowing whether it was incorrect.—
According to Cook (p 152 of my Book)3 the reef lies from to 1 & mile from shore (with profound water close outside) & with 10 to 30 fathoms within.—
On the side generally visited by shipping the reef is much broken. The Americans perhaps do not know of the submerged & probably dead part of the reef,4 encircling part of the island described in Nautical Magazine in 1836.;5 —& this is the part of the coast of Tahiti, where in Cooks chart, the Barrier is least perfect.— I did not colour it without consideration.—6
Hooker has been here a week & has been working at his Paper on Coal Plants7 & we have had much interesting conversation. He has been reading with more attention, he says, than he did before all Bunbury’s paper,8 & several times he has been expressing his admiration at them.
Ever yours | C. Darwin
Comments on investigation of coral reefs by A. A. Gould, particularly the reefs around Tahiti. Mentions description of reefs of Tahiti by W. Forbes.
Hooker’s view of work by C. J. F. Bunbury.