52 



REPORTS ON THE STATE OF SCIENCE. — 1915. 



Seismological Investigations. — Twentieth Report of the Gom- 

 mittee, consisting of Professor H. H. Turner {Chairman), 

 Professor J. Perry (Secretary), Mr. C. Vernon Boys, 

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

 Dr. E. T. Glazebrook, Mr. M. H. Gray, Professor J. 

 W. JuDD, Professor C. G. Knott, Sir J. Larmor, Professor 

 E. Meldola, Mr. W. E. Plummer, Professor E. A. Sampson, 

 Professor A. Schuster, Mr. J. J. Shaw, Sir Napier 

 Shaw, and Dr. G. M^. Walker. 



[Plates I., II., III., IV.] 



I. 



II. 



III. 



IV. 



V. 



VI. 



VII. 



VIII. 



IX. 



X. 



XI. 



XII. 



XIII. 



XIV. 



Contents. 



General Notes, Accounts 52 



Stations {Destruction of Instruments at Cocos) .54 



Seismic Activity in 1911, 1912, 1913. (Discussion deferred) ... 55 



Distribution of Milne's Epicentres, 1899-1910 55 



Improvements of the Milne Seismograph 56 



The Milne-Shaw Seismograph 57 



The Milne-Burgess Seismograph 68 



Di^irnal Wanderings of the Traces 58 



Insect Disturbances of Seismographs 66 



~" " ~ " ~" " . . 67 



. . 73 



. 74 



. 74 



. . 74 



The Identification of S : Suggestion of a New Phenomenon Y 

 Correction of Tables deferred 



Shide Bulletins 



New Method of Computation 

 Standardizing a Milne-Shaw Seismograph 



I. General Notes, Stations, and Registers. 



The Committee asks to be reappointed with a grant of 60L in addition 

 to the annual grant of lOOL from the Caird Fund already voted. 



The two years which have elapsed since the death of John Milne 

 provide a sufficient experience for an approximate budget for carrying 

 on the work he had organised, with such natural developments as are 

 mentioned below and liad already been initiated by him. The accounts 

 for one vear stand thxis : 



Receipts. 



(1) Brit. Assoc. Annual Grant . £60 



(2) „ „ Printing . . 70 



(3) Gray Fund 40 



(4) Royal Society . . . .200 



(5) Brit. Assoc. (Caird Fund) . 100 



Total .... £470 



Expenditure 



(A) Salaries 



(B) Printing 



(C) Rent . 



(D) Shide Station . 



(E) New machines, &c. 



£240 

 80 

 20 

 65 

 65 



£470 



On the receipts side the items are arranged in historical order. Item (1 ) 

 dates practically from the appointment of the present Committee (as 

 the fusion of two former Committees of the Association) in 1895 (Ipswich). 

 The first grant to the Committee was 80/. Subsequent grants have 

 fluctuated in amount, but tlie average annual grant in the twenty years 

 1895-1914 is almost exactly 60?., which has been the uniform grant since 

 1908. When observing stations had been established over the globe 



