THE HURRICANE, THE TYPHOON, AND THE TORNADO. 19 
great storm, but the accounts seem not to have been sufficiently 
clear to justify the statement. Of the electrical state of the air 
there is no doubt, but observations on earth magnetism were not 
then understood or thought of in the island. It is said that 
heavy showers of salt water occurred. 
In both the accounts here given, and in all the recorded ac- 
counts of hurricanes in the northern hemisphere, the fact of the 
spiral motion, the extreme force, and therefore velocity of the 
Avind in the storm, the comparatively slow motion of the 
whole storm in path, and the backing of wind from north by 
west to south, and thence by east to north, are facts made per- 
fectly clear. It has often happened that ships at a distance of 
twenty or thirty miles from the storm, and not in the line of its 
path, have failed to notice anything extraordinary in the weather ; 
and on land the storm has sometimes swept through a forest, 
throwing dovm trees in various directions in its path, but injuring 
nothing on either side. This has been noticed in England as 
Avell as in the tropics, and is indeed a familiar fact. 
The coincidence of earthquake shocks with hurricanes may 
be only accidental, but as it is certain that both events are 
frequently, if not always, accompanied by electrical and mag- 
netic disturbances, and that earthquakes are almost always 
indicated by barometric changes, it would be unsafe and un- 
philosophic^ to deny that the earthquake and the storm are 
without mutual connection. It is not indeed easy to explain 
how or why this is the case ; but the fact being determined by 
observation the theory will soon adapt itself. Earthquake 
shocks have also been often accompanied by falls of meteoric 
stones, and these again very frequently by storms and hurricanes. 
The earthquake shocks have usually been recorded as near the 
central axis of the storm, and also near the time of its com- 
mencement. It is only of late that observations of earth mag- 
netism have been made and recorded ; but it is now well known 
that the telegraph wires, especially those nearly meridional 
(proceeding from the north to the south), are altogether unusa- 
ble for signals during great storms, owing to the surcharge of 
magnetic electricity passing through them in the form of earth 
currents. 
Lastly, the great sea-wave that is produced by the sudden 
alteration of atmospheric pressure in the central part of a 
tornado (amounting sometimes to one-tenth of the whole pres- 
sure), multiplied as all such waves are when they enter narrow 
funnel-shaped channels, is at once an illustration of the nature 
of the storm and the cause of some of its most fatal results. 
This Avave approaching the land rises and rushes over the sur- 
face, sometimes rising twenty or thirty feet or more above the 
ordinary sea-level, and in its forward and return motion sweeps 
