Royal Institution of Great 



WEEKLY EVENING MEETING, 

 Friday, January 23, 1920. 



/- 



General E. H. Hills, C.M.G. D.Sc. F.R.S., Secretary and 

 Vice-President, in the Chair. 



The Hon. Sir Charles Parsons, K.C.B. Sc.D. 

 LL.D. F.R.S. M.R.I. 



Researches at High Pressures and Temperatures. 



The subject to which I wish to direct our attention this evening- is 

 Researches at High Temperatures and Pressures. 



Just ten years ago, in this room, Sir Richard Threlfall discussed 

 the effects of temperature and pressure on various substances, and 

 commenced by referring to a suggestion I made in 1904 to sink a 

 bore hole 12 miles deep in the earth with the object of exploring 

 the region beneath us, about which so little is known. Last summer, 

 at Bournemouth, I ventured again to direct attention to the desir- 

 ability of such an exploration in the interests of science generally, 

 and to the possibility that it might ultimately lead to some develop- 

 ments of practical importance and utility. 



Ten years ago no experiments had been made on the behaviour 

 of rocks under the conditions existing at great depths below the 

 surface of the ground ; but prompted by my suggestion in 1904, 

 and some subsequent correspondence in regard to the possibility of 

 the rock crushing in and closing the shaft, Professor Frank D. Adams, 

 of McGill University, Montreal, commenced experiments on the 

 strength of rocks to resist the closing np of cavities under the con- 

 ditions prevailing at great depths below the surface. He published 

 the account of these experiments in 1912, in the Journal of Geology 

 for February of that year. 



Adams' method was to place a block of granite or limestone in a 

 tightly fitting cylinder of nickel steel which was shrunk lightly 

 around the block to ensure perfect fitting and support ; hard steel 

 rams actuated by a hydraulic press were arranged to press against 

 the ends of the block with a known pressure. Two small holes were 

 previously drilled in the specimen, one axial in the centre and one 

 transverse, the diameter of the holes being 0'05 inch, or one-tenth 

 the diameter of the specimen. The temperature of the container and 

 specimen were maintained at any desired point up to the softening 

 point of steel. In some experiments no heat was applied, in others 



Vol. XXIII. (No. 114) b 



