4 Earthquakes and Electricity. [January, 
known to occur in connection with it. That the separated 
agencies composing this electricity should be in constan 
motion in the magnetic field or orb from the Equator to- 
wards the Poles is what is to be expeCted ; . . . hence . . . 
we have manifestations of motion (rendered megulai y 
induction and by geological causes) in the shape of earth- 
currents. The polar accumulations of electricity . . . would 
explain the attraction of the earth's poles on those of other 
magnets. To the same fat of. dense accumulation of elec- 
tricity at or near the magnetic and terrestrial poles . . . 
would be attributed the manifestations of silent continuous 
discharges . . . seen under the form of aurorae. And it is 
conceivable that the eletricities, in their motions . . . to- 
wards the poles, are occasionally forced ... to accumulate 
for a time at certain places on the surface ; and when this 
should occur in regions where clouds . . . were frequently 
present, the necessary conditions for the development of 
thunderstorms would apparently be obtained. Lastly, if the 
. accumulations should occur in certain portions of the 
earth’s crust . . . insulated from each other, and below 
though not far removed from the surface, and especially in 
regions where clouds . . . were habitually absent (as in 
Chili and Lower Peru), there would appear to be possible 
causes for the occurrence of earth explosions manifested by 
earthquakes ” (pp. 156—160). In regard to the term explosion 
here used the writer is now inclined to consider the nature 
of an earthquake discharge as an electrical leak rather than 
as an electrical explosion. 
In the “ Athenaeum ” of July 8th, 1882,. a review of the 
last-mentioned work was given. The reviewer noticed the 
portions relative to terrestrial electricity in the following 
terms : — “ The earth-sprung lightnings which so constantly 
form an attendant phenomenon on volcanic eruptions, and 
the subterranean thunder which at times resembles the artil- 
lery fire of a naval engagement, are at once faCts that sup- 
port the view given in this book of the functions of the 
terrestrial condenser, and hints that the diligent pursuit of 
the enquiry may yield much valuable information as to the 
general theory of eleCtric storms, aerial, super-terrestrial, 
or sub-terrestrial.” . . . “ It is from the co-ordination of the 
indications given by the barometer, the seismometer, and 
the various appliances for measuring eleCtric and magnetic 
force and direction, that we must hope to arrive in due time 
at the true theory of eleCtric storms, of which we take 
thunder and lightning to be one form and earthquake 
another.” 
