Vol. 6$.~\ OCHIL EARTHQUAKES OF 1900 TO 1907. 367 



whole area, it is 89 within the isoseismal 6, 82 between the iso- 

 seismals 6 and 5, and 79 between the isoseismals 5 and 4, most of 

 the places at which the sound was inaudible being close to the latter 

 curve. In describing the sound, 24 per cent, of the observers com- 

 pared it with passing waggons, etc. ; 16 per cent., with thunder ; 8, 

 with wind ; 10, with loads of stones falling ; 24, with the fall of a 

 heavy body ; 16, with explosions ; and 2 per cent., with miscellaneous 

 types. The crash or thud was again a marked feature of the sound, 

 but the greater proportion of comparisons with passing waggons 

 and thunder is indicative of its more rumbling character and longer 

 duration. 



The beginning of the sound preceded that of the shock in 49 

 per cent, of the records, coincided with it in 44, and followed it 

 in 7 per cent. ; the end of the sound preceded that of the shock in 

 15 per cent, of the records, coincided with it in 55, and followed 

 it in 30 per cent. The duration of the sound was greater than 

 that of the shocks in 44 per cent, of the records, and equal to it 

 in 56 per cent. 



(11) 1905, September 22nd, about 1.30 a.m. 

 A tremor was felt at Alloa and Bridge of Allan. 



(12) 1905, September 25th, early morning. 



The exact time at which the shock occurred is unknown. A 

 tremor, evidently very slight, was felt at Alloa and Cambus. 



(13) 1905/ September 30th, 9.45 p.m. 



A slight shock was felt by many residents in Menstrie, accompanied 

 by a rumbling noise, as if a heavy body were being rolled along the 

 ground and bumping every now and then. 



(14) 1905, October 29th, 10.53 a.m. 



An earth-sound was observed by many residents in Menstrie. ~Eo 

 shock was felt ; the sound resembled distant thunder passing from 

 north-west to south-east. 



(15) 1905, December 22nd, 9.15 p.m. 

 A slight shock was felt throughout the village of Menstrie. 



(16) 1906, July 3rd, 2.15 p.m. 



A slight shock, of intensity 3, was felt at Menstrie, accompanied 

 by a sound like the fall of a heavy body. 



(17) 1906, July 4th, 3.45 a.m. 



Intensity, 4. Number of records, 9, from 6 places, and 11 negative records 

 from 10 places. 



The shock was felt at Airthrey, Alva, Blairlogie, Menstrie, Eed 

 Carr, and Tullibody, all of which are in the Hillsfoot district. The 



