296 Charles Davison— British Earthquakes. 
miles ; and the observations on the time-relations of the shock and 
sound show that the slip must have died out slowly towards the 
south-east and rapidly towards the north-west. Lastly, the obser- 
vations at. Isle Martin and Inverbroom on the first direction of the 
vertical motion would seem to indicate that the relative movement 
of the rock on the downthrow side must have been downwards, that 
is, that the slip must have increased the throw of the fault and 
possibly also tended to increase the depth of Loch Broom. 
Authorities.—Besides those already mentioned I am indebted to 
the following observers for accounts of this earthquake: Achduart, 
Miss M. MacLennan; Inverlaal, Mr. M. M‘Lean; Kildonnan, Mr. 
A. McKenzie; Lochinver, Mr. A. Beveridge; Morefield, Mr. A. Ross ; 
Scorraig, Miss A. Cameron; Ullapool, Rev. J. MacMillan. The 
account of the shock at Ullapool given above is taken from a ~ 
paragraph (probably copied) in the ‘‘ Birmingham Daily Post” for 
March 7, 1892. 
S. W. Cornwatt Hartraquakes: May 16-17, 1892. 
During the night of May 16-17 two distinct earthquakes were 
felt in south-west Cornwall, the first at about 22h. 30m. on May 16, 
the second and stronger at about Lh. 30m. on May 17. According 
to one report (from Porthleven), several shocks of a slighter 
character were felt in the interval between them; but, this being 
the only evidence I have been able to obtain, their occurrence must 
be regarded as doubtful though it is worthy of notice that Porthleven 
is one of the five places where the principal shock was most severe. 
I may refer here to a report printed in several newspapers that, 
on the afternoon of May 17, the water in Mount’s Bay, and especially 
in Penzance Harbour, was tinged with a decided yellow colour; 
and this was generally considered, I believe, as a result of the earth- 
quake. But Mr. J. Morrish, Dock and Harbour Master at Penzance, 
informs me that this discolouration had been noticeable for at least 
a fortnight previously. Whatever may have been its origin, it cannot 
therefore, as he observes, have had any connection with the shocks. 
First Shock: May 16. 
Time of occurrence, about 22h. 30m. Intensity, 1V. Epicentrum, 
about 14 miles N.E. of Wendron, i.e. in lat. 50° 8’ 30’ N., long. 
5° 13’ 5” W. 
This shock, being the first and also an exceedingly slight one, was 
felt or recorded by very few observers. I possess only nine accounts 
from eight different places, namely, Breage, Budock, Manaccan, 
_ Mawgan-in-Meneage, Nancegollen, Perran-ar-Worthal, Porthleven, 
and St. Stythians. At Breage, the intensity of the shock was IV. 
and a loud rumbling sound was heard, lasting two or three seconds. 
At Mawgan-in-Meneage, the noise, which was not so loud as that 
of the principal shock, seems to have been the only phenomenon 
observed. From all the other places, the records consist of little 
more than the statement that a slight shock was felt. 
The boundary of the disturbed area is shown on the map by a 
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