General Characters of the Disturbance. 37
might perform several oscillations before coming to rest, and
each of these to-and-fro movements, if sufficiently pro-
nounced, would by some observers be considered as a distinct
shock.
The evidence appears sufficiently conclusive that more
than one " shock " (not in the sense of an oscillation) was
felt in the area of damage, and of the various records which
appear in the report I am disposed to attach the most
weight to the statement of Mr. Larman, the chief officer of the
Coastguard Station at West Mersea, who gave us a very dis-
tinct account of his having experienced two shocks, each
preceded by a report, the first being the stronger and louder.
It is possible that the first was the direct shock and the
second the shock reflected from the Colne Valley at "Wiven-
hoe, there being a certain amount of evidence, as will be seen
later on, that such reflection actually occurred.18
Beyond the area of damage, and especially at the remote
stations, there are numerous records of two distinct shocks
having been felt. This is the case, for instance, among
other places, at Walton-on-the-Naze, West Ham, Sudbury,
Cheltenham, Leamington, West Haddon, Market Harbo-
rough, Dover, and in London. With respect to the latter
place I was enabled to question the observer, Mrs. Carvalho,
of Inverness Terrace, soon after the occurrence, and I am
satisfied that the "two shocks" in this case meant two
distinct series of vibrations, separated by a short interval.
This lady happened at the time to be lying in bed reading,
the volume being held balanced in such a position as to
render it extremely sensitive to any movement, and the
pause in the vibration of the book was particularly described.
As will be seen in the descriptive report, the experience
of many of the observers at the above-mentioned places
appears to have been of a very similar character.
18 The fact that a sound preceded each shock favours this interpreta-
tion rather than the alternative explanation that the two shocks indicated
the successive arrivals of the normal and transverse waves. It is, of
course, also possible that there were two distinct initial disturbances, but
this does not seem probable.