Vol. 58.] INVERNESS EARTHQUAKE OF SEPTEMBER 1901, 391 
r. October 22nd, about 10.15 a.m. 
Number of records 2, from 2 places. 
The only records of this earthquake come from Aldourie and 
Drumnadrochit. At Aldourie, eight or nine sounds were heard 
between 9.45 4.4. and noon. The sound here at about 10.15 a.m. 
was very distinct, and resembled the roar of a furnace when the door 
is open, or of an underground train; it lasted 2 or 3 seconds, and 
seemed to travel eastward. No distinct shock was felt, but there was 
evidently a very weak tremor. At Drumnadrochit only a sound 
was heard, like distant thunder, growing louder and dying away. 
The focus lay probably beneath Loch Ness, 
October 22nd, 12.55 2.m.: Drumnadrochit.— A sound, like 
distant thunder, without any accompanying tremor. 
October 22nd, 8.20 p.m.: Bunchrew.—A slight tremor, accom- 
panied by a rumbling sound. 
October 22nd, 8.25 p.w.: Bunchrew.—A rumbling sound. 
November 5th, 12.12 a.a.: Dalarossie.—A rumbling sound, like 
thunder, not loud, lasting about 4 or 5 seconds, without any 
sensible shock. 
s. November 15th, about noon.. 
An underground rumbling sound was heard by several persons at 
Dochgarroch. 
November 15th: near the end of Loch Ness.—An underground 
rumbling sound was heard during the night. 
November 21st: Dochgarroch.—A slight vibration and rumbling 
sound were observed during the night. 
Sound-Phenomena of the After-Shocks. 
Many accounts of the after-shocks are little more than mere 
records of their occurrence. If we exclude these, the percentage 
of audibility of all the after-shocks is 77. hat of the shock of 
September 18th, 3.564.m., is 62; and of the shock of Sept- 
ember 30th, 80. Omitting these shocks, the percentage is 85, 
showing that the sound, though much fainter than that which 
accompanied the principal earthquake, was nevertheless a com- 
paratively important feature. | 
Taking all the after-shocks together, the comparisons of the 
sound to passing waggons, etc., occur in 26 per cent. of the records, 
to thunder in 43, wind in 7, loads of stones falling in 2, the fall 
of a heavy body in 2, explosions, etc., in 17, and miscellaneous 
sounds in 3 per cent. Omitting the two strongest after-shocks on 
September 18th and 30th, the corresponding figures are: passing 
waggons, etc. 33, thunder 33, wind 5, and explosions 28. These 
are about the proportions met with in slight earthquakes, and 
indicate that, as a rule, the foci of the after-shocks were of small 
linear dimensions, 
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