110 
NATURE 
[May 29, 1902 
Cicero, in the “De Divinatione,” says that ‘God has 
not predicted so muchas the divine intelligence of man” 
and omitted reference to the intelligence of the lower 
animals, it seems probable that in certain directions the 
instinct of brutes is not to be overlooked. 
The small earthquakes which frequently precede a 
volcanic eruption are usually referred to as abortive 
attempts made by internal forces to establish an open- 
ing. But should all such earth shakings be regarded in 
this manner? It seems likely that some of them may 
be simply intermittent yieldings in the general process 
of rock folding, which, when it has sufficiently relaxed 
its hold upon the imprisoned vapours, allows the same 
to burst forth as an eruption. Whether before the erup- 
tion there were unusual escapes of gas from subterranean 
sources, whether there had been changes in colour, taste, 
level or temperature of the water in wells and springs, 
we have not yet been told. 
Neither have we been told of any prophet who boldly 
came forth and announced the impending danger ; but 
what we do know is that whilst the Governors of the 
Windward and Leeward Islands are yet striving to allay 
the fears of terrified inhabitants, thoughtless Cassandras 
are predicting tornados, new eruptions, and even the 
sinking of the islands. As we have said before, tornados 
always occur in these islands between July and October, 
and volcanic displays usually sink back into quiescence in 
an intermittent manner. To call attention to what is 
inevitable in terms suggesting that even greater catas- 
trophes than have yet been experienced are to be ex- 
pected, may make sensational paragraphs and cheapen 
property. It can, however, only excite alarm, create 
panic, trouble the civil administration and accelerate the 
depopulation of the islands, and therefore prognostications 
of this character should at least be discouraged. What 
grounds there are for supposing that the Antilles may 
sink beneath the ocean is a mystery. Cinder heaps which 
have risen above the ocean as volcanic islands have by 
the action of the waves been reduced to shoals, but with 
the Antilles we are dealing with a fold in the crust of our 
earth which, if the water was removed from its flanks, 
would stand up like a chain of mountains 18,000 feet in 
height. Parallel with this is the fold of the Cordilleras, 
with its peaks 12,000 feet in height, bounded by an ocean 
more than 14,000 feet in depth. 
It seems that it was an adjustment in this latter fold 
which took place on April 19, when several towns were 
ruined and more than 1000 people lost their lives, 
which led to adjustments announced by earthquakes in 
the parallel Antillean fold. Pelée then smoked, indicating 
that pressure had been relieved. This relief suggests 
elevation, and that elevation rather than subsidence is 
the direction of movement in these islands is testified by 
a variety of geological evidence. 
From this it would seem that, instead of issuing an 
alarming prediction that the West Indies are to disappear 
from view, the recent eruptions suggest that they have 
risen to a greater height, whilst the water on their 
Caribbean side may have deepened. Two wrinkles on 
the face of the world have probably gained in height, 
whilst the depth of the bounding furrows on their 
western flanks has probably been increased. As indi- 
cations of these changes, newspapers state that Richmond 
in St. Vincent has risen, whilst a French cable ship has 
found at a certain spot an increase in the depth of water 
of nearly 500 fathoms. 
The public are evidently anxious that volcanic erup- 
tions and seismic disturbances should be predicted, but 
as districts where these activities prevail are not trans- 
parent and we cannot see what is happening beneath 
our feet, neither are we able to measure the pressures 
and strains which may be increasing in such regions, the 
time when a ball rising on a mast will announce impend- 
ing subterranean disturbances seems very distant. Still, 
NO. 1700, VOL. 66] 
there are directions in which investigations bearing on 
this point may be pursued. One of these would be to 
determine whether before a volcanic outburst or after the 
same there were any unusual changes in level in opera- 
tion. Lyell remarks that if we reflect upon the dates of 
the principal oscillations noted near the Bay of Naples, 
there appears to be a connection between the movements 
‘of upheaval and a local development of volcanic heat, 
whilst periods of depression are concurrent with periods 
of volcanic quiescence. The part that the horizontal 
pendulum would play in such an investigation is obvious. 
A second-line of research would be to determine 
whether the movements of magnetic needles placed in 
the vicinity of a volcano show any relationship to its 
eruptions. We know that many lavas are highly 
magnetic, and it is not unlikely that physical and 
chemical changes, together with mechanical displace- 
ments of such materials, would result in changes in 
magnetic elements in their vicinity ; and that remarkable ~ 
coincidences between such changes and volcanic erup- 
tions have taken place has been indicated by Captain 
E. W. Creak, F.R.S. 
There may be other lines of research which would 
throw light upon subterranean operations, but these are 
two which might be pursued without great difficulty. 
On the Sequence of Events. 
From the enormous displacements of ground which 
have frequently accompanied world-shaking earthquakes, 
and from the fact that their origins can be traced to dis- 
tricts where we have evidence of secular movements 
which may be yet in progress, it is not unreasonable to 
suppose that such earthquakes are announcements that 
strains have suddenly been relieved in certain orogenic 
foldings. This relief may be compared to the movement 
of a key which fires many mines. Not only might 
volcanic vents beneath which there was excessive 
pressure burst into activity along the fold, but similar 
displays might be expected in neighbouring folds. In 
support of these views attention may be called to the 
fact that the mountain-making epochs in geological 
history were periods of intense volcanic activity. From 
the middle to the end of the eighteenth century, earth- 
quakes and volcanic eruptions were frequent throughout 
the world. The history of the large earthquakes of 
Japan shows an approximate coincidence in time between 
these phenomena and volcanic eruptions, and similar 
coincidences can be adduced from the registers of other 
countries. 
Evidences of this description suggest a relationship 
between pronounced seismic efforts in or near a volcanic 
region and volcanic activity, and when we know the 
sequence of events which have recently occurred in the 
West Indies and Central America, our knowledge of the 
relationship between earthquakes and other subterranean 
phenomena may be extended. The seismograms 
reproduced in Figs. 1 and 2 are of interest in this 
connection. 
On April 19 at about half-past two in our time, the Cor- 
dilleras of Central America were suddenly relieved of 
seismic strain, villages and towns were shattered, earth- 
quake waves passed all over our world and all through 
the same, whilst in the epifocal area we learn that at one 
town alone 1100 people lost their lives. Whether this 
widespread disturbance was quickly followed by adjust- 
ments in the neighbouring Antillean ridge we are not 
certain. All that can be gathered from newspapers is 
to the effect that aéou? the end of April many small earth- 
quakes took place and Mont Pelée smoked and rumbled. 
On May 3 this mountain was in eruption and ashes fell 
upon St. Pierre. Two days later it ejected a stream of 
mud and commenced its work of serious destruction. 
The sea receded 300 feet, and the Puerto Plata and the 
Dominica-Martinique cables were interrupted. On this 
