General Character* of the Disturbance. 81
reason for doubting the fact that on a calm spring morning
vorticose movements may suddenly arise in the atmosphere—
such phenomena are in fact too common to excite special
attention. Looked at in the " dry light" of Science, however,
there is not the slightest reason in the present state of know-
ledge for connecting these atmospheric movements with the
earthquake, except as coincidences. With still greater
scepticism must be received the statements of a Tillingham
correspondent, that " as soon as the shock had passed, a
sulphureous vapour was noticed to arise," and of another
observer at Wivenhoe, who asserts that a bright steel cork-
screw was found tarnished after the earthquake, as a result of
the disturbance !
In point of fact the evidence is conclusive that no special
meteorological conditions preceded, accompanied, or succeeded
the disturbance of last April in direct relationship to that
event. The barometer and thermometer had been rising
since the previous day, and on the morning of April 22nd
the sky was in most parts clear, with bright sunshine and
occasional clouds, the wind N.E. or N.N.E, and very light.
Both before and after the shock light showers fell in some
parts of the country; and at Ely, Canon Joy reports that a
heavy hailstorm fell a few minutes before the disturbance.
Mr. A. H. Cocks, M.A., of Thames Bank, Great Marlow,
states that a party on the Thames at Temple Lock also
experienced " a very hard squall immediately preceding the
shock." Readings of the barometer and thermometer, given
by various observers, will be found in the body of the Report.
From these it will be seen that the barometer at Halstead
stood at 29.808 inches and the thermometer at 48°; at
Faulkbourne the readings at 8.30 a.m. were, bar. 30.02 in.,
therm. 52°; at Ipswich bar. 30 in., therm. 40°; and at
Norwich an aneroid barometer indicated 29.8 in.
Nature and Duration of the movement; number of shocks and
subterranean noise.—To the older seismologists an earthquake
was simply a wave of elastic compression passing through
the materials of the earth's crust, and causing the particles at
the surface to oscillate to and fro in a closed curve, the