Diigald Bell — The " Great Buhnergencer 27 



It is in the regions D and F, those nearest the central area, 

 that the change of frequency is most marked ; and, as it takes place 

 during the month following the great earthquake, it is difficult 

 to resist the impression that the relation between them is one of 

 eifect and cause. The frequency curves for these two districts are 

 shown in greater detail in Figs. 2-5. They correspond to 1, 2, 4, 

 6, 8, and 10 epicentres per rectangle. Figs. 2 and 3 refer to the 

 region D, and illustrate the distribution of epicentres during the 

 epochs preceding and following the principal earthquake, namely, 

 from January 1, 1885, to October 27, 1891, and from November 1, 

 1891, to December 31, 1892. Figs, 4 and 5 relate to the region 

 Jb' for the same two epochs. The apparently aimless character of 

 the curves during the earlier epoch in the region F, and their more 

 definite form during the later in both regions, seem to me to point to 

 the advent of new conditions governed by a simple law ; and, 

 in my opinion, there can be little doubt that the change was 

 determined by the great earthquake of 1891. 



A 



V. — The " Great Submergence " Again : Clava. 



By DuGALD Bell, F.G.S. 



FEW years ago, in one of three or four papers treating of the 

 " high-level shelly clays " of Scotland, I referred at some 

 length to the interesting section at Clava, near Inverness, first 

 described by Mr. Jas. Fraser, C.E., and inquired — Is it part of an 

 old sea-shore or bottom, laid down by the sea where we now find 

 it, and therefore proving a submergence of at least 500 feet ? ^ 



I submitted a number of facts and considerations which, I 

 thought, tended to show that this instance at Clava cannot be 

 received as a satisfactory proof of submergence. 



Since that time, the Report of the Committee of the British 

 Association on the deposit has been published. It disclosed a 

 difi'erence of opinion on this point among the members, the majority 

 holding that the deposit is really in situ, and indicates a sub- 

 mergence of over 600 feet: while a minority thought the shelly 

 clay may have been transported by land-ice, as in other well-known 

 instances, and that this supposition was attended by fewer difficulties 

 than the theory of a " great submergence." 



The subject has again been brought up by Mr. John Smith, who 

 visited the section once while the Committee's investigations were in 

 progress. That single visit has been prolific in results. It enabled 

 Mr. Smith offhand, without waiting for the Keport, to instruct the 

 public regarding the deposit ; and it enables him now to pronounce, 

 with all confidence, as to which section of the Committee is in the 

 right.^ As we have no pretension to be so swift and sure in our 

 methods of working, we ask leave, in our old-fashioned way, to go 

 over the ground again, and to restate, as concisely as we can, the 



1 Trans. Geol. Soc. Glasgow, vols, ix, x, 



2 Geol. Mag. for November, 1896. 



