2 The East Anglian Earthquake.
widely felt earthquakes, since numerous records exist
showing that shocks of considerable strength, and extending
over wide areas, may fail to produce any structural damage,
either on account of the great depth of the focus, or, among
other reasons, because the epicentrum happens to be far
from damageable structures.1
It was at first contemplated to have given a complete
chronological catalogue of all the earthquakes that had been
recorded in Britain, as no such catalogue at present exists.
Mr. William White had kindly volunteered to co-operate in
this work, and nearly 350 had been entered down to the end
of the year 1843, when we discovered that a similar task was
being undertaken from another another point of view, by
Prof. J. P. O'Reilly, of the Royal College of Science of
Ireland (See Trans. Roy. Irish Acad., vol. xxviii., Science,
p. 285). This circumstance, together with the fact that such
a general catalogue would have been beyond the scope of the
present report, led us to abandon the original scheme and to
confine ourselves to those earthquakes which had caused
structural damage, the result of our joint labours being given
in the list below. Mallet's British Association Catalogue,
which ends in 1842, has been taken as the basis of our list,
and by diligent literary research, we have been enabled
to add several well-authenticated shocks which had escaped
the notice of this eminent seismologist. For the earlier
records I am indebted to Mr. C. L. Prince, F.R.A.S., of
Crowborough Observatory, Sussex, who was good enough to
copy out and transmit a list of earthquakes from a rare work
in his possession, entitled 'A General Chronological Table of
Meteors, Weather, Seasons and Diseases,' probably by Dr.
Thomas Short, F.E.S., in two vols., Loudon, 1749. It
seemed desirable to ascertain, if possible, where the author of
this work had taken such very early records from, and Mr.
White having failed to find a copy of the book in the British
Museum Library, I applied to Mr. Prince, who wrote:—" He
1 The epicentrum is the point on the earth's surface vertically over
the focus or centrum, the line joining the centrum and epicentrum
corresponding to the " seismic vertical " of the older seismologists.