The Sun.
London, England, 1870-08-16 00:00:00

DANGEROUS RESERVOIRS.

The catastrophe which makes the turning incident of
Mr. Charles Reade's latest novel, " Put Yourself in his
Place," viz., the inundation of the town of Hillsborough
by he bursting of a reservoir, may have seemed to many
readers somewhat improbable. But a precisely similar
disaster happened in England some years ago, causing
the loss of many lives, and the last mail brought an
account of a calamity which recently befel the town of
Rhymney. A violent thunderstorm so flooded the reservoir
of the Rhymney Iron , Company, from which the
town was supplied with water, that it first over-
flowed and then burst its embankment, carrying away a
house just underneath. This reservoir was two miles
from the town. The volume of water rushed down the
valley, sweeping everything before it—horses, cattle, and
human beings, j ust as we had it described for us in Mr.
Reade's picturesque pages. For miles we are told, articles
of household furniture, and' carcases of pigS and sheep,
could be seen floating on the stream. The town itself
was reached and houses in it flooded. and
dkuilaged. Apart from the-loss-of life, the damage
to property, of course, is great in such accidents,
not to speak of the injury it causes to agriculture. And
with such fatal precedents before them, it seems strange
that the constructors of reservoirs in England do not take
greater precautions against these disasters. In this
country, so far as we know, no similar catastrophe has
ever taken place. Floods we have had, disastrohs to
life and property, but always from the rising of streams,
swollen by spring tide freshets, or tide waters, raised un-
usually high by storms. An inundation from the
bursting of a reservoir is, we believe, unknown -to
us There seems no good reason why it should
sulbe equally unfamiliar in England, unless we are to
pose gross and constant ignorance or carelessness in the
location and construction . of reservoirs in that country.
It may be well to observe. that the flood at Rhymney was
only one of a series throughout the country, caused by
unusually severe thunderstorms, which are ascribed to the
extreme sultriness of the weather. We have 'furnished
the conditions, are we to have the same effects ? Perhaps
our meteorologists can tell. If so, they will re der a
ag
gileater service in putting farmers on their guard ainst
these violent convulsions of nature, than by prophesytig:
more hot weather or registering the fluctuations of the
thermometer. New- York Times.

THE MIGRATION OF BUTTERFLIES OVER

THE ISTIIMUS.

Very useful and salutary lessons have been taken from
the habits and instincts of the lower animals. We all
remember how the busy bee was made use of 'in our school
tasks to point out the value of industry and perseverance,
as well as the ant from time immemorial, for its foresight
and wisdom. Brunel, one of our- greatest modern engi-
neers, is said to have taken a hint from a species of boring
mollusk in constructing and , overcoming the difficulties
met with in the Thames Tunnel ; and another
animal, when wounded in its contests with the
snake, has pointed out the plant to be used as
an antidote. The butterflies, so gorgeous in coleuring,
yet fragile in form, although apparently useless as regards
man, have, notwithstanding, had their wonderful Meta-
morphosis taken as explaining the mysteries of life,
death, and resurrection. Somewhere about the end of
June or beginning of July there appears annually on the
Isthmus of Panama myriads of a very beautiful species of
butterfly. Its general colour is a deep velvety black,
crossed with bars of golden green, with the posterior
wings prolonged into two tail-like elongations
with white tips. It is the Urania Leilus of
naturalists. While out on the bay we lately noticed a
few species flitting eastward, as usual over the water. In
some years they are few, while in others they come in
clouds, like dry leaves driven before the east winds, and
so thick and near the earth that boys amuse themselves
by knocking them down with branches of trees. No; ob-
stacle can make them deviate from their .east course. On
coming against the base of hills, houses or high walls they
rise upward until they can pass over. We have seen the
swallows occasionally prey upon them for the sake of
their thick moth-like bodies (which in the females are
filled with ova) leaving the beautiful wings strewed on the
beach. Where they come from and whither they
are going is yet a mystery. We have seen
them occasionally alight on a flowering tree, which bota- ,
nists call cordia, apparently to enjoy its flowers-and take
a rest ; fanning themselves when in repose ith their
gold striped wings, like a young beauty after the fatigues
of the ball-room. We have been unable to ascertain
how far north the geographical 'distribution of -this
species extends, . but it is • mentioned in Madame
Merian's account of the butterflies of Dutch Guiana,
although neither in her work nor in any more
modern have •we seen its peculiar migratory habits
spoken of. We should be glad if any of our readers,
living to the east of Panama, about the river and valley
of the Bayano, would inform us whether thpy had ever
noticed the species in question, and if so, whether as a
resident or periodical visitor to. the neighbourhood• we
would also beg a similar 'favour from our intelligent
friends in the- Central American Republics. We: should '
thus be enabled 'to get at the geographical range of this
beautiful migrating butterfly. In visiting the museums
of natural history kin Europe, one is not only struck
with admiration at the immense variety of animal
life displayed ; but also with regret at how
little is known of - the • life and habits of those
that are foreign. What are the conditions that render
this-species exceedingly-npnierous in one season and very
few the next, have yet to be found Out.. It is now well
ascertained thA' the numbers of animals of any species
does not depend at ad on threir Prolific increase, but upon
'its adaptation to the conditions of its life. The scientific
study of butterflies has led Mr. Wallace (whose book on
the' Malay 'archipelago- we noticed some time ago) to
deduce veryimportant confirmations of the " theory of
natural- seleCtions ; " not the least _interesting are those
peculiarities in form and colouring which become to them
a defenfe against their enemies. We have noticed:
similar contrivances among many of the other Butterflies;
of the Isthmus, althstugh not to the same wonderful:
extent as Mr. Wallace's inquiries led him to find out'
among the Butterflies of the Island of Sumatra. He gives
the following account of them in his new work on con-,
tributions to the theory of natural selection." lie says :----
" I myself had the good fortune to observe scores of
kallima paralekta in Sumatra • and to capture many
of them, and can vouch for the accuracy of the
following details ; These butterflies frequent dry
forests and fly very swiftly. They were
never seen to settle on a flower or a green
leaf, but were many times lost sight of in a bush or tree
of dead leaves. On such occasions they were generally
searched for in vain, for while gazing intently at the very'
spot where one had disappeared, it would often suddenly
dart out; and again vanish twenty or fifty yards further
on. On, one or two occasions the insect was detected re-
posing, and it could then be seen how completely it assi-
milates itself to the surrounding leaves. It sits on a nearly
upright twig, the wings fitting closely back to back,
concealing the attennae and head, which are drawn
up between their bases. The little tails of the hind wing
touch the, branch and forma perfect stalk to the leaf,
which is supp-otted in its place by the claws of the middle
pair of feet, which are slender and inconspicuous. The
irregular outline of the wings gives exactly the perspec-
tive effect of a shrivelled ieaf. We thus have size, colour,
form, markings and habits, all combining together to pro-
duce a disguise which may be said to be absolutely per-
fect ; and the protection which it affords is sufficiently
-indicated by the abundance of the individuals that
possess it."—Panama Star and Herald.

Colonel Wilson, RE., is about to resign the Pro-
fessorship of Fortifications at the Royal Military Aca-
demy, Woolwich: Major Stuart, R.E., will be promoted
to the vacancy.