EARTHQUAKES OP NOV. If, TO DEC. 11, 1890. 



631 



slips so slight in extent, and therefore so short in period, that the 

 vibrations produced by tliom were p(5r(;ei)ti])le only as earthquake- 

 sounds *. The st rain, being thus relieved along the l)ranch fault, was 

 in consequence immediately increased along the main fault ; and, 

 within half an hour, the strain there was relieved, hut only partially, 

 and for nearly another month the relief was at intervals continued 

 by slight slips, varying both in surface-position and in depth, the 

 last slip of all being the most important which took place along the 

 main fault. 



" It is by no means impossible," says Prof. Lapworth in con- 

 cluding his well-known paper on ' The Secret of the Highlands,' 

 ^' that the long straight .... and so-called anticlinal valleys of 

 the Scottish Highlands, such as those of the Great Glen and Loch 

 Tay, walled in by steep hill-slopes and occupied by lakes of profound 

 depth, are nothing more than greatly depressed interment synclinal 

 troughs, owing their origin to the same causes which bring about 

 the slow secular elevation and approximation of their flanking 

 ranges '' f. It wiU be obvious that, so far as regards the Great 

 Glen, the conclusions arrived at in this paper are in close accordance 

 with the above suggestion ; but, whatever view may be held on this 

 subject, there can be little doubt that the recent earthquakes of 

 Inverness were the transitory records of changes that, by almost 

 indefinite repetition in long past time, have resulted in the great 



Highland faults. 



A^II. Authorities. 



Some of the facts recorded in this paper are taken from the 

 accounts published in two local newspapers, the 'Inverness Courier' 

 for Nov. 18, 21, and Dec. 16, and the 'Northern Chronicle' for 

 Nov. 19, Dec. 3 and 17. 



But for by far the greater and more valuable part I am indebted 

 to the kindness of numerous ladies and gentlemen who answered 

 my enquiries either addressed to them personally or contained in 

 letters published in the newspapers above mentioned. The follow- 

 ing list contains the names of my correspondents, with the excep- 

 tion of a few who have expressed a wish that their names should 

 be withheld : — 



Abernethy, Kev. W. Forsyth, D.D. ; Achanalt, Mr. J. Taylor ; Achnacarry, 

 Mr. W.Sharp; Alehousehillock (Cairney), Kev. A. Fiddes, B.D. ; Aldourie, 

 Mr. J. Donald ; Alness, Rev. W. L. Wallace Brown ; Ardgay, Mr. W. T. Brown ; 

 Auldearn, Rev. J. Bonallo ; Aultguisli Inn, Mr. D. Mackay ; Aviemore, Mr. J. 

 S. Lawrence ; Avoch, Rev. J. Gibson ; Balnafettack, Mr. J. Birnie ; Beauly, 



* On the following occasions sounds, possibly seismic, were heard and 

 recorded by a single observer: — 



Nov. 12, about 1'', Inverness. A rolling noise heard. 



Nov. 14, about 23'* 30'", Torbreck. Four distinct noises heard, resemblinj^ 

 distant cannon. 



t Geol. Mag. (1883) p. 344. 



