J. D. Dana on the Consolidation of Corai Formations. 357 
Ship, the leakage was actually large, and it will probably be 
not far from the truth to put this at 15 per cent. more. We thus 
obtain a reduction of thirty per cent. in all, while the engines fell 
as far as fifty per cent. below their aggregate theoretic power. 
The remaining deficiency can hardly be accounted for, but by 
supposing that the air coudd not be heated by furnaces and regen- 
erators both together, to a sufficient degree and with sufficient 
rapidity to maintain the theoretic pressure, and the assumed velo- 
city of piston. "This explains the statements made by reporters 
present on the trial trip, that the temperature of the working cylin- 
der did not rise above 440°, and also Capt. Ericsson’s repeated 
assertions that he could not carry more than 8 pounds of pres- 
sure. And this may satisfactorily explain the published state- 
ment which has remained for two months uncontradicted, that 
the original plan of heating the air has been entirely abandoned. 
The results to which this investigation has brought us, are less 
encouraging than were anticipated, or than, in the beginning we 
even desired to find them. We are compelled to look, at present, 
much less hopefully upon this invention than we have been dis- 
posed to do heretofore ; so much less so, as to apprehend that it 
can never come into successful use as a Motive power. 
Univ. of Alabama, Aug. 30, 1853. 
Arr. XXXVII—On the Consolidation of Coral Formations ; 
y James D. Dana. 
At the Cleveland meeting of the American Association for the 
Advancement of Science, in August last, Prof. Horsford read a 
labored reply to the writer’s criticisms* of his views, on the con- 
solidation of coral limestone. This paper by Prof. Horsford, has 
appeared in several daily newspapers, and has thus had a wide 
circulation. Deeming the public papers no proper place for sci- 
entific controversy, either for attacks or replies, and knowing 
that an author may not hold himself responsible for the accuracy 
of articles thus published, the writer had intended to take no 
notice of the arguments of Prof. Horsford, until they had appeared 
elsewhere. But on finding evidence in the date of the reading of 
