276 



8h. 4' 57" p.m., and Acheruar at its eastern elongation at 8h. 49' 40" p.m., 

 and the difference of their readings was 76° 10' 34" . To find their 

 azimuths A and B. 



Tan. 1 (A— B) = Tan. i (A + B) Tan. i (D + E) Tan. i (D— E) 

 Log. Tan. h (A— B) = Log. Tan. 4 (A + B) + Log. Tan. i (D + E) + Log. 

 Tan. h (D— E) 



= Log. Tan. (.38° 5' 17") + Log. Tan. (63° 19' 10") + Log. Tan. (5° 29' 35") 



= 9-8941851 + 10-2987972 + 8-9830243 



= 9-1760066 

 Tan. h (A— B) = 8° 31' 45" 



^ (A + B) = 38° 5' 17" as observed 



1 (A— B) = 8° 31' 45" as above. 



Therefore by adding and subtracting these equations we get — 

 A = 46° 37' 2" and B = 29° 33' 32" 



A EEJOmDER TO ME. A. B. BiaaS'S CEITICISM 

 ON OBSERVATIONS MADE IN EESPECT OF THE 

 "OBSEEVED PEEIODICITY OF THE DEATH 

 EATE," Etc. 



By R. M. Johnston, F.L.S., Etc. 

 [Bead Novemler 17, 1884.] 



I am glad to see tliat so able a critic as Mr. Biggs has 

 taken up the important subject of the " Death rate in its 

 observed coincident relation to super-terrestrial phenomena," 

 which was recently introduced by me in a paper read before 

 this Society ; although, at the same time, it is to be regretted 

 that he has based his remarks upon a brief abstract from a 

 newspaper rather than ujjon the paper itself, for it has 

 greatly misled him as regards the nature and scope of my 

 argument. 



It appears to me to be very clear that Mr. Biggs's diffi- 

 culty is caused chiefly by erroneously assuming that the 

 relations commented upon are simjple instead of comjjlex, and 

 that belief in a more or less striking observed coincidence 

 seems to be regarded by him as synonymous with a like 

 belief in a corresponding mtitualiiiter-dejoeiidencehetween the 

 matters which have been observed to coincide. 



Now there is a very wide difference between the concej)tion 

 or conviction of a known agreement or coincidence and the 

 conception of an underlying causal relation. We can fairly 

 conceive and admit of identity of movement or action 

 between several phenomena for a limited space of time 

 without prejudice, even when we assume that such coin- 

 cidence is not uninterrupted for a longer period, or that it may 

 be due (1) to mutual inter-dependence alone ; (2) to cause's 



