THE 



AiMERlCANJOURNALOFSCIENCE 



[FOURTH SERIES.] 



Art. XI. — An Investigation into the Elastic Constants of 

 Rocks ) more especially with reference to Cubic Compres- 

 sibility; by Frank D. Adams and Ernest G. Coker. 



Introduction. — In a paper published in 1901 an account 

 was given of an investigation into the deformation of marble 

 under varying conditions of heat and pressure.* Under a 

 grant from the Carnegie Institution of Washington to F. D. 

 Adams, the experimental investigation into the behavior of 

 rocks under pressure has been continued in the laboratories 

 of McGrill University. As the investigation went forward, 

 however, it was found necessary to follow out several separate 

 lines of research, the results of which it is proposed to present 

 in a series of separate papers. 



In the present article a brief resume is presented of the 

 methods adopted and the results obtained in an investigation 

 into the elastic constants of rocks, more especially with a view 

 to ascertaining the amount of cubic compression which rocks 

 will undergo when submitted to pressure from every side, 

 all rocks of course being subjected to such compression to a 

 greater or less extent, previous to the deformation which they 

 suffer under conditions of differential pressure. 



A full presentation of the results of the investigation will be 

 found in a Publication of the Carnegie Institution of Wash- 

 ington, ~No. 46, having the same title as the present paper, and 

 which is now in press, to which the reader is referred for full 

 details of all the measurements carried out in the case of each 

 of the specimens examined, as well as for detailed descriptions, 



* Adams, F. D., and Nicolson, J. T. An experimental investigation into 

 the Flow of Marble. Phil. Trans. Eoyal Soc. London, Series A, vol. cxcv, 

 pp. 363-401. 



Am. Jour. Sci.- 



7 



-Fourth Series, Vol. XXII, No. 128.— August, 1906. 



