36 Election of Officers and Members of Council. [Feb. 



multiplied by tlie difference between the times observed. From the 

 well-known property of the hyperbola that the difference between the 

 focal distances of any point of the curve is constant, it follows that the 

 sound must come from some point of a hyperbola having the two ob- 

 serving stations as its foci, or, if allowance be made for the curvature of 

 the earth's surface, from some point of a hyperboloid of revolution. 

 When there are several observing stations, each pair of stations gives 

 a definite locus for the origin of the sound, and if the point common to 

 all these loci can be determined, this point must be the one required. 



It is unnecessary to enter into the details of calculations necessary 

 for the determination of this common point, which are given at con- 

 siderable length in the essay. The writer has also given the modifica- 

 tions of the calculation caused by the variations of the velocity of sound 

 and other causes. 



Babu Chandrakanta Basu being present in the meeting, the 

 President pi'esented him with the medal and prize money, adding a few 

 words of congratulation and encouragement. 



The President then delivered an address. 



(The Address has been printed separately from the Proceedings). 



A cordial vote of thanks was proposed by Sir A. W. Croft to 

 the Hon. Sir C. A. Elliott for his address and for his services to the 

 Society, which was carried by acclamation. 



The President announced that the Scrutineers reported the result 

 of the Election of Ofiicers and Members of Council to be as follows : — 



President : 

 C. J. Lyall, Esq., M.A., L.L.D., C.S.I., CLE. 



Vice-Presidents : 

 Dr. A. F. R. Hoernle. 

 Sir A. W. Croft, M.A., K.C.I. E. 

 The Hon. Sir C. A. Elliott, K.C.S.I. 



Secretaries and Treasurer : 

 G. A. Grierson, Esq., C.S. 

 Dr. J. H. TuU Walsh. 

 Dr. A. W. Alcock. 

 C. R. Wilson, Esq., M.A. 

 Pandit Haraprasad Sastri, M.A. 

 C. Little, Esq., M.A. 



