368 DE. CHARLES DAVISON ON THE [Aug. I907, 



shock is described as a quivering thud, strongest at the beginning, 

 and lasting 2 seconds. The sound was heard by all observers, and 

 was compared by two with the fall of a heavy body, and by two others 

 with an explosion. 



(18) 1906, July 7th, 5.29 a.m. 



Intensity, 4. Number of records, 5, from 2 places. 



The shock was felt at Alva and Menstrie. The sound was heard 

 by all observers, and was compared by two with the fall of a heavy 

 body. 



(19) 1906, August 24th, 5.25 p.m. 



A very slight, but unmistakable, shock was felt at Menstrie. 



(20) 1906, September 28th, 12.25 p.m. 



A slight shock was felt at Blairlogie, Menstrie, and Red Carr, and 

 was accompanied by sound. 



(21) 1906, October 3rd, 4.32 a.m. 



A shock, strong enough to awake several observers, was felt at 

 Blairlogie and Menstrie. The shock consisted of two vibrations, 

 and the accompanying sound was like a distant cannon-shot. 



(22) 1906, October 8th, 7.24 a.m. 



Intensity, 5 ; centre of isoseismal 4, in lat. 56° 10-9' N., long. 3° 51 -3' W. 

 Number of records, 23, from 14 places, and 8 negative records from 6 places 

 (fig. 3, p. 369). 



The average of 17 estimates of the time is 7.24 a.m. The 

 disturbed area, which is bounded by an isoseismal of intensity 4, 

 is 12 miles long, 9| miles wide, and 90 square miles in area, its 

 centre being 2 miles north of Menstrie. The intensity of the shock 

 was 5 at Logie, Menstrie, and Tillicoultry. At these places, the 

 shock was very distinctly felt, consisting as a rule of one prominent 

 vibration. Its average duration was 2 seconds. The sound was 

 heard by 86 per cent, of the observers, and in 57 per cent, of the 

 records was compared with the dull concussion caused by the fall of 

 a heavy body. The beginning and end of the sound either preceded 

 or coincided with the corresponding epochs of the shock. 



(23) 1906, October 8th, 8.16 a.m. 



Intensity, 4. Number of records, 10, from 8 places, and 3 negative records 

 from 3 places. 



A much slighter shock than that at 7.24 a.m., was felt at Airthrey, 

 Alva, Blairlogie, Bridge of Allan, Dunblane, Logie, Menstrie, and 

 Red Carr. The disturbed area was probably about 9| miles long, 

 6 miles wide, and 45 square miles in area, and its centre about 

 2 miles 1ST. 5° W. of Menstrie. The shock consisted of two 

 vibrations, lasting not more than 2 seconds, and was accompanied 

 by a sound resembling that of a muffled explosion. 



