196 REPORT— 1873. 



who was in the garden. So strong, indeed, and concurrent is the evidence 

 on this point that no doubt can remain about it, in regard to almost all the 

 localities from which communications have been received ; the slight discre- 

 pancy among the witnesses to the fact may be accounted for by some of 

 them being resident on a soil composed of soft alluvium, and others upon a 

 rocky surface. Some of the witnesses notice that the sound was instanta- 

 neously repeated with even greater violence. 



The shock instantly followed the noise or sound ; and its occurrence was 

 marked in many ways : houses were shaken, doors and windows made to 

 rattle, suspended objects to oscillate ; in one house bells were set a-ringing 

 with violence, in another they were strongly agitated ; jugs, basins, and 

 water-glasses in bedrooms, apothecaries' bottles, phials, and pots, the glasses 

 in the pump-room at Bridge of AUan Spa were heard to knock against one 

 another and seen to move ; a chimney-mirror, loosely fastened, was thrown 

 down ; and chimney ornaments were dashed upon the floor. 



Next succeeded that most appalling of all the attendant circumstances of 

 an earthquake, the sensation as of a heaving impulse or wave, giving the 

 idea of a crest and declivity, instantly followed by a double vibration, the 

 whole duration being from three to four seconds. The statements of the ob- 

 servers (as made known in the various reports) on whom one feels that most 

 reliance is to be placed from their previous expei'ience, habits of close ob- 

 servation, and the circumstances in which they were placed at the time, 

 all go to show that the undulation came from a direction W. or N.W., some 

 observers making the direction exactly opposite by not distinguishing the 

 first impulse from the recoil or restoration of the wave-surface. One ob- 

 server, on whom the utmost reliance can be placed, had the most distinct 

 feeling of vertigo or dizziness arising from the undulation, a sensation so 

 strong that a few moments' continuance of it would have produced nausea — 

 a strong testimony to the reahty of the wave-motion. 



The extent of country throughout which this earthquake was felt is 

 greater than that of any which has occurred since this inquiry was under- 

 taken. The limits are marked by Stirling and Blair Logic on the S.E., and 

 St. Fillans on Loch Earn and Glen Lednock on the N.W. The shock was 

 feebler at these limits than in the parts intermediate, as Bridge of Allan, 

 Dunblane, Greenloaning, Ardoch, and Crieff. In regard to the breadth of 

 country agitated, I have been unable to determine that it extended more 

 than two or three miles from the vaUey of the Allan Water, the concussions 

 recorded being greater to the east of that valley than in the opposite direc- 

 tion, while in the village of Doune, four miles west, they do not seem to 

 have been noticed. The want of self-recording instruments, the extreme 

 difficulty of determining the exact instant of the occurrence of an event so 

 sudden and startling, render it impossible to attempt any definite statement 

 as to the progress of the wave, which, so far as instrumental indication can 

 serve us, seems to have emanated from near Comrie. All the observers who 

 have attempted to specify an exact time have, to aU appearance quite inde- 

 pendently, agreed that it was, as above stated, at 10" past 4'' p.m. Persons 

 trained to observe, or self-recording instruments, alone can furnish reliable 

 data in such a case for indicating the time occupied in the undulation pass- 

 ing from point to point. The intensity upon the Comrie scale, which ranges 

 from 1 to 10, was of a medium force, about 4. 



The geological formation of the tract of country embraced wdthin the 

 above limits varies greatly. The lower part of the village of Bridge of Allan 

 is situated upon the alluvium of the I'orth valley, in which, as far up from 



