292 Charles Davison—British Earthquakes. - 
terms of the Rossi-Forel scale.1 The epicentrum is really an area, 
the projection of the seismic focus or centrum on the earth’s surface. 
As, however, I have no means of determining the form of this area, 
T have given instead, the position of the point vertically, or nearly 
so, above the centre of intensity of the focus. 
On the maps, the position of the epicentral point is indicated by 
a star. Places where the shock was felt is indicated by small black 
discs ; those where it was not felt (by several or many persons) by 
small circles. A cross drawn through a disc or circle indicates that 
the usual earthquake-sound was also heard there; a cross alone, that 
the sound was the only phenomenon recorded, but not necessarily 
implying that the shock was not also felt. 
List oF HartTHquaKkes 1n 1892. 
In the following list, only those shocks are recorded that were 
felt by at least two observers. For the notes relating to those at 
Invergarry and Ardochy, I am again indebted to Mr. John Grant 
and Mr. Murdoch Matheson, who have continued their valuable 
work of recording the earthquakes of that part of Inverness-shire. 
Mr. Matheson informs me that all the Ardochy shocks were felt 
by at least four persons. 
Feb. 29, 22h. 385m., Ardochy. A slight shock, accompanied by a 
low rumbling noise: duration of sound, 40 seconds. 
» 2h. 15m., Ardochy. Duration of shock, about 15 seconds: 
intensity, IV.; preceded by a low rumbling noise. 
Mar. 4, about 7h. 80m., Loch Broom. 
Apr. 8, Th. 85m., Ardochy. A slight shock like the passing of a 
carriage. 
May 16, about 22h. 30m., South-west Cornwall. 
 Lieaboute tate. 0m. 
Aug. 17, about 2dh. 30m.., ss Bun brelzestiven A slight shock. 
» 18, Oh. 23m., South-west of Pembrokeshire. A sound like 
distant thunder heard. 
» >» Oh. 25m. Principal earthquake (intensity, nearly VIII.), 
felt most strongly in Pembrokeshire, but perceptible 
throughout nearly all Wales, in the west and south-west 
of England and the south-east of Ireland; disturbing at 
least 26 counties. 
,, Oh. 87m., Pembrokeshire. 
5» » about lh. 5m., Pembrokeshire. A very slight shock. 
» » about lh. 40m., Pembrokeshire and adjoining counties, 
Devonshire and Wexford. The strongest shock but one 
of the whole series. 
about 2h. 40m., Pembrokeshire. 
» » about 4h., South- west of Pembrokeshire. A slight bhdele 
,, 22, about il. 55m., Pembrokeshire. 
Sep. 25, 3h. 13m., Tnvergarry. A rumbling noise, lasting about 4 sec. 
1 A translation of the Rossi-Forel scale of seismic intensity is given in the GEOL. 
Mag. Dec. III. Vol. VIII. p. 58; Nature, vol. xlil. 1890, p. 349. 
