32 REPORTS ON THE STATE OF SCIENCE. — 1919. 



4. Seismology after the War. By G. W. Walker, A.R.C.Sc, M.A., 



F.R.S. 



The lamented death in 1913 of that great pioneer of earthquake investi- 

 gation, Dr. John Milne, followed only two years later by the untimely 

 demise of Prince Boris Galitzin, left the young art of seismometry 

 poor indeed. 



The war now ended has rendered impossible for many years to 

 come those friendly personal relations with German seismologists 

 which some of us valued very highly, and has also given the quietus 

 to the International Association of Seismology. 



It is with sadness and diffidence that I agree to the request of the 

 British Association Organising Committee, Section A, to give some 

 outline of my views as to the future of the subject, more especially 

 as the matter is not solely a scientific one, but involves also the 

 question of finance and policy. As to the precise meaning and scope 

 of seismology, different opinions may reasonably be held. 1 sympathise 

 with the view entertamed by some geologists that the name has been 

 appropriated by physicists to a subject tiiat has little to do with 

 earthquakes. That is so, for to the modern seismologist, unless he 

 happens to live in a seismic region, tlie eai-thquake is of interest only 

 in so far as it reveals the internal dynamical properties of the earth. 



Others hold the view (which 1 share) that all phenomena revealed 

 by seismograplis, such as microseisms, earth tides, and the cognate 

 theoretical problems of the form and distortion of the earth, are properly 

 included in seismology. 



It has been mj privilege for some years to apply the principles 

 of seismology to the study of small-scale artificial earthquakes, and, 

 althougli I cannot give details at present, I have the greatest confidence 

 in saying that a rich practical hai-vest is in promise. 



The name ' seismology ' is probably not the best for the wide field 

 of investigation that is possible by means of seismographs. After all, 

 it is really the application of dynamics to the earth, and thus the 

 term ' geodynamics, ' recently used by the Cambridge Committee, strikes 

 me as being an eminently suitable one for the subject, and one to 

 which little objection could be taken. 



There is perhaps no other subject in which the need for international 

 co-operation and a widespread distribution of observing stations is more 

 cleai'ly evident. This was recognised by Dr. Milne, and it would 

 be a lasting disgrace to this country if the scheme he established were 

 allowed to fall tlirough for want of financial support. Doubtless the 

 scheme requires revision, and the' instruments should be brought up 

 to date, while stations which are clearly insufficient or unsuitable might 

 be abandoned or replaced by others. 



But this raises the question of what scheme is feasible and ef&cienl 

 and most likely to be generally conducive to progress. 



From time to time, largely as the result of individual effort, different 

 branches will attain prominence and they may require special legis- 



