Europe suffered more than the south, and in Nystad, Finland, the
galvanometer indicated an intensity of current equal to that of 200
Leclanche cells.

Since thunderstorms are generally local, it is only natural that their
effect upon telegraph cables should also be confined to one locality.
Numerous careful observations, carried out over considerable periods of
time, show that the disturbing influences of thunderstorms on telegraph
lines are of less duration and more varying in direction and intensity
than those of the aurora borealis. Long lines suffer less than short
lines; telegraph wires above ground are more easily and more intensely
affected than underground cables. It is, however, possible, that this is
mainly due to the fact that in the districts where strict records were
kept, in the German Empire, most of the long lines are underground
cables, while most of the short local lines are overground wires. The
results of the disturbances varied; in Hughes's apparatus the armatures
were thrown off, lines in operation indicated wrong signs, dots became
dashes, and the spaces were either multiplied in size or number,
according to the direction of the earth currents induced by the
thunderstorms. Since these observations extended over nearly 2,000
cases, some conclusions might fairly be drawn from them. For the purpose
of a more complete knowledge on this subject, Dr. Wykander recommends a
series of regular observations on earth currents to be carried out at
different stations, well distributed over the whole surface of the
globe, these observations to be made between six and eight A.M., and at
the same time in the evening. Special arrangements to be made at various
stations to record exceptionally intense disturbances during the
phenomena of the aurora borealis, notice to be taken of time, direction,
intensity, and all further particulars. Since this question appears to
bear a considerable amount of influence on underground cables, it is one