REPORTS ON THE STATE OF SCIENCE. 



Seismological Investigations. — Twenty-first Report of the Com- 

 mittee, consisting of Professor H. H. Tubnee (Chairman), 

 Mr. J. J. Shaw (Secretary), Mr. C. Vernon Boys, Dr. J. E. 

 Crombib, Mr. Horace Darwin, Mr. C. Davison, Sir F. W. 

 Dyson, Dr. K. T. Glazebrook, Professor C. G. Knott, 

 Professor H. Lamb, Sir J. Larmor, Professor A. E. H. Love, 

 Dr. H. M. Macdonald, Professor J. Perry, Mr. W. E. 

 Plummbr, Professor H. C. Plummer, Dr. E. A. Sampson, 

 Professor A. Schuster, Sir N.\pier Shaw, Dr. G. T. 

 Walker, and Dr. G. W. Walker. 



[Plate I.— Fig. 5.] 



CONTENTS. PAGE 



I. Personal 29 



II. General Notes and Bulletins 30 



III. Diurnal Wanderings of the Trace . 30 



IV. Suggested Device for Avoiding Loss of Traces 32 



V. A Simple Device for the Better Timing of Seismograms . . . .33 



VI. Ledgers for each Station .... 33 



VII. The Stereographic Method of Finding an Epicentre 35 



VIII. Dr. Klotz's Tables 38 



IX. Tables for P and S at Distaiices exceeding 110° — Suggestion of Essential 



Change in Tables near Epicentre 39 



X. General Preliminary Discussion of the 1914 Results 53 



I. Personal. 



The Committee has to lament the loss by death of Mr. M. H. Gray, 

 Professor J. W. Judd, and Professor R. Meldola. The former was on 

 many occasions a generous supporter of Professor Milne's pioneer work; 

 the extension of the Milne Earthquake Observatory at Shide was ren- 

 dered possible by his aid; and his gift of 1,000Z. founded the Gray 

 Fund. Professor Judd was Chairman of the Committee from 1899 to 

 1906 (Fourth to Eleventh Eeports). It is impossible to open this Eeport 

 without a brief reference to the great loss to Seismology in the recent 

 death of Prince Galitzin. Had circumstances been more propitious, he 

 was to have been in England this summer as Halley Lecturer at 

 Oxford. But the war threw a great deal of responsible work upon 

 him : indeed, it seems probable that the strain may have been too great. 

 His invaluable services to Seismology are too well known to need 

 comment. 



At the last meeting of the Committee (Manchester, September 8, 

 1915) Professor J. Perry resigned the office of Secretary, which he had 

 kindly filled temporarily, on the emergency caused by the death of 

 Professor Milne. Mr. J. J. Shaw was elected Secretary. He has 

 during the past year shared with the Chairman the visits of superin- 



