REPORTS ON THE STATE OF SCIENCE, 



Etc. 



SEISMOLOGICAL INVESTIGATIONS. 



Thirty-seventh Report of Committee (Dr. F. J. W. Whipple, Chairman ; 

 Mr. J. J. Shaw, Secretary ; Dr. C. Vernon Boys, Dr. J. E. Crombie,^ 

 Sir F. W. Dyson, Sir R. T. Glazebrook, Dr. Wilfred Hall, Dr. H. 

 Jeffreys, Sir H. Lamb, Prof. H. M. Macdonald, Prof. E. A. 

 Milne, Mr. R. D. Oldham, Prof. H. H. Plaskett, Prof. H. C. 

 Plummer, Prof. A. O. Rankine, Rev. J. P. Rowland, S.J., Prof. 

 R. A. Sampson, Mr. F. J. Scrase, Sir Napier Shaw, Capt. H. Shaw, 

 Sir F. E. Smith, Dr. R. Stoneley, Sir G. T. Walker). 



This is the thirty-seventh Report of the Committee appointed by the 

 British Association for Seismological Investigations, the Committee having 

 been formed in 1895 by the amalgamation of two committees. One of 

 these committees had been appointed for the investigation of Earth Tremors 

 in this country and had presented five reports, whilst the other, with John 

 Milne as the moving spirit, had been investigating the Earthquakes and 

 Volcanic Phenomena of Japan for fourteen years. Thus the British Asso- 

 ciation has given continuous support to seismology for fifty-one years. 



Up to his death in 191 3 the reports of the Committee were prepared by 

 Milne, and from that date onwards to his own death in 1930 Prof. H. H. 

 Turner, Chairman since 1907, was responsible not only for the reports but 

 for the organisation of the greater part of the work recorded in them. 



Since 1 92 1 , the year in which the Seismological Section of the International 

 Geodetic and Geophysical Union was constituted, the principal care of the 

 Committee has been the International Seismological Summary. This is 

 a publication in which details are given of all the instrumental records of 

 earthquakes occurring in any part of the world. Returns, known as seismo- 

 logical bulletins, are transmitted from all observatories to Oxford, where 

 the observations for each day are transcribed on cards. By comparison of 

 the observations the epicentre of every appreciable earthquake and the time 

 of occurrence are determined. The distance of each observatory from the 

 epicentre is computed , as well as the times of transmission of the waves 

 which are revealed by the various phases of the seismograms. Finally, for 

 the ' preliminary tremors,' which correspond with the primary waves of 

 compression and distortion, the times of transmission are compared with 

 standard tables. The results of these calculations are tabulated for printing 

 and duly checked. It will be seen that the preparation of the Summary is 

 a task of considerable magnitude. It occupies fully the time of three persons. 



The International Seismological Summary was initiated and developed by 

 Prof. Turner. He left the work well organised. In accordance with the 

 wishes of the University authorities, the routine has been continued at the 

 University Observatory during the two years that have elapsed since his 

 death. His successor in the Savilian Chair of Astronomy, Prof. H. H. 

 ^ Dr. Crombie died on August 6, 1932. 



