230 REPORTS ON INVESTIGATIONS AND PROJECTS. 



which will have the effect of covering a maximum amount of territory 

 without undue overlapping. 



So far as learned, this is the only laboratory anywhere in which 

 the same order of accuracy that is expected in more strictly physical 

 investigations has been attained in the study of mineral solutions. 

 At the time when this standard was set grave doubts were entertained 

 as to the feasibility of handling physical phenomena at high tempera- 

 tures with anything like the certainty attained at ordinary tem- 

 peratures, but the experience of this first year has justified the effort, 

 and this standard will not be modified in any particular at present. 



INVESTIGATIONS ON FLOW OF ROCKS. 



Frank D. Adams, McGill University, Montreal, Canada. Grant 

 No. 227. (For previous reports see Year Book No. 2, p. xxxiv, 

 and Year Book No. 3, p. 119.) $1,500. 



During the past year the investigation of the cubic compressibility 

 of rocks has been completed and the results are now ready to send 

 to Washington for publication by the Carnegie Institution. 



In this investigation Young's modulus and Poisson's ratio were 

 determined by direct measurements on short columns of the rocks 

 selected, which were submitted to stresses in a 100- ton Buckton test- 

 ing-machine. From these values that for the cubic compressibility of 

 the rock and also the modulus of shear were calculated. The rocks 

 selected for measurement, 16 in number, were typical representatives 

 of the acid and basic plutonic intrusi ves, together with certain marbles. 

 These rocks, being massive and isotropic, fulfilled the conditions 

 required for accurate measurement by the method employed, while 

 at the same time the plutonic intrusions represent, so far as our knowl- 

 edge goes, the rocks constituting the mass of the earth's crust. An 

 investigation into the elastic constants of plate glass was also made 

 for purposes of comparison with the results obtained in the case of 

 rocks. 



These determinations will afford data for the mathematical treat- 

 ment of a number of great problems in geophysics. 



The investigation of the flow of rocks has also been continued. 

 The methods formerly applied to the study of the flow of marble have 

 been extended to various impure limestones, dolomites, etc., such as 

 the lithographic limestone of Bavaria (Solenhofen limestone), the 

 black Belgian marble, and the dolomites of Cockeysville, Maryland, 

 and of Lee, Massachusetts. 



