260 Proceedings of the Royal Society of Edinburgh. [Sess. 
district, namely, Alva, Gogar, Logie, Menstrie, Sauchie, Tillicoultry, and 
Tullibody. The disturbed area was much smaller than that of the pre- 
ceding shock, and probably it did not extend so far as Dunblane, 
Greenloaning, Blackford, and Glendevon, and must therefore have contained 
less than 80 square miles. 
The shock was as if a very heavy body had fallen on the floor, followed 
by the quivering which such a fall would produce. Its duration was one 
Fig. 2. — Earthquake of July 23, 1905. 
and a half or two seconds. At Menstrie, the noise was as loud as thunder 
overhead. 
(9) 1905, August 3, about 6 p.m. 
A very perceptible shock, felt by several observers at Red Carr. 
(10) 1905, September 21, 11.33 p.m. (First Principal Earthquake.) 
Intensity, 6; centre of isoseismal 5 in lat. 56° IT'8 N., long. 3° 49'1 W. ; 
number of records, 139, from 57 places, and 22 negative records from 19 
places (fig. 3). 
On the map of the earthquake are shown three isoseismal lines of 
intensities 6, 5, and 4. The isoseismal 6 is 13 miles long, 8 miles wide, and 
