between the flash and the report may be taken
as a basis for calculation by any one with
nerve sufficient to time a thunderstorm by
the minute hand of his watch.

Pliny says it never thunders in Egypt.
Plutarch that it never thunders in
Abyssinia. We know now that both of these
assertions are mistakes, though indeed Egypt
is singularly exempt from frequency of
storm; for storms are correspondent with
rains, and, as it seldom rains in Egypt,
thunders and lightnings are equally rare.
It never rains in Lower Peru, or so rarely as
to be outside all meteorological consideration;
consequently, say at Lima, storms of thunder
and lightning are as little known as
hurricanes of wind and rain. Storms are also rare
at the North Pole, and never occur in
midseas, at a certain distance from land. The
rainy days at Cairo are only three or four in
the year, the storm days are about the same
number. At Calcutta the average of storm
days is sixty, and everywhere a broad parallel
is kept; so that, where there is most rain,
there is also most thunder and lightning.
Storms come at the same times and seasons,
and with striking regularity. In the tropics
they accompany the wet seasons and the
change of the monsoons: at Calcutta, with
its sixty days of storm, not one occurs in
November, December, or January: at
Martinique and Guadaloupe none are known in
December, January, February, or March. In
mean latitudes very few storms occur in
winter, and only a few in the hottest days of
spring and autumn: more than one half come
in summer, and generally in the day—rarely
at night, either in the tropics or in the temperate
zones. But the rule of summer storms
does not hold absolutely for all places; for, on
the western coast of America, and the eastern
shores of the Adriatic, more occur in winter
than in summer; in Greece more in autumn
and spring; in Rome there is no difference
between summer and autumn; at Bergen
and at the Azores, where there are winter
rains, they are most frequent in the cold and
rainy weather; at Kingston in Jamaica it
thunders every day for five consecutive
months, though the adjacent islands are
tranquil; also at Popayan in Columbia,
during a certain season, there is thunder
every day.

Woods, mountains, and broken land cause
and attract storms; but their frequency is
not always referable, to the configuration of a
district. At Paris, for instance, the average
number of thunder-days is fourteen; and
Paris is not on a dead level; while at
Denainvilliers, between Orleans and Pithiviers, one
of the flattest districts possible, the average
is raised to twenty-one. Other atmospheric
causes, then, must be in operation which are
not yet made fully manifest, and which
remain to be investigated.

There are three kinds of lightning, says
Monsieur Arago: forked, sheet, and spherical.
Forked lightning comes in very slender flashes,
generally white, but is sometimes blue or violet
coloured. Fine as these flashes are, they
often divide into three or more branches: as,
when in seventeen hundred and eighteen,
twenty-four churches were struck in the
environs of Saint Pol de Léon, but only three
peals of thunder were heard. The flashes of
forked lightning are most destructive. They
are nowhere seen to more terrible perfection
than when lighting up the dark ravines and
black precipices of a mountainous district.
Even in England, among the Cumberland
mountains, the thunder-storms have a majesty
and awful sublimity which no dweller on the
plains can understand. Sheet lightning is
comparatively harmless. Some of those
thunderless summer lightnings are distant
sheet lightnings, too distant to allow of the
thunder, which yet exists, being heard. Dark
red, blue, or violet are the principal colours
of this form of electricity, which has neither
the whiteness nor the swiftness of the forked.
Spherical lightnings are what are called
vulgarly, thunderbolts; luminous masses, or
fiery globes, which descend slo wly to the earth,
and make lightning conductors useless. On
the night of the fourteenth of April, seventeen
hundred and eighteen, Deslandes saw
three globes of fire fall on the church of
Couesnon near Brest, and destroy it
utterly; and, on the third of July, seventeen
hundred and twenty-five, during the
height of a thunder tempest, an enormous
globe of fire fell, and killed a shepherd and
five sheep. This was not so terrible, though,
as the Ethiopian storm, reported by Abbadie,
which destroyed two thousand goats and the
goatherd by one single flash. We quote these
assertions modestly, if somewhat doubtfully;
not presuming to place a limit to the wonderful
forces of nature, of which the more we
learn the less we seem to know, yet expressing
ourselves humbly on the uncertainty of
testimony, and the proneness to exaggeration
common to humanity. The balance between
scepticism and credulity is the most difficult
of all balances to hold evenly.

Those summer lightnings, of which we
have spoken, have been taken by some to
mean essentially harmless interchanges of
electricity; the atmosphere seeking its own
electrical equilibrium. But it will generally
(not always) be found that, during their
appearance, there has been a storm somewhere
on earth, where, what was but lambent
summer lightning to the far-off spectator,
has proved to be deadly destructive fire to
some hapless dweller underneath. In a July
night of seventeen hundred and eighty-three,
De Saussure, at the Hôpital de Grimsel,
under a calm clear sky, saw, in the direction
of Geneva, a thick band of clouds, which gave
out thunderless lightnings. This was but
summer lightning to him; but the Genevese
were suffering all the horrors and ravages
of a storm such as the oldest inhabitant