, 1875-12-29

the Equator to the Poles. Glaciers and ice
bergs increasingly evaporate cendensation and
precipitation are as unceasing in dew, rain,
snow, or hail, but precipitation differs from
evaporation in his the atmosphere holds evapo-
rated water in a transparent state as a sponge
holds water in a fluid state; and as a,sponge
may be charged with water and may be carried
with it to a distance to be discharged by squeez.
Ing' SO the atmosphere is charged with invisible
yapour, which is water in this form, and this
vapour is carried from the ocean over the land,
where, by contact with mountain saapges,. the
atmospheric sponge is squeezed, the JTapour is
reformed into water, and falls in the form of
rain. A sponge holds water by capillary attrac-
ton; the atmosphere holds water as invisible
Vapour by latent heat, and it is the liberation
OF this latent heat by condensation which brews
up the tremendous tornadoes, storms, and foods
which work so much damage. The water
evaporated during many days from, say, 10000
square miles will be precipitatcd in a few days
over a few square miles. Hence the devasta-
ting foods occasionally experienced, In nature
excess begets excess, which work on until the
forces necessary to excess have for the time
become worked out. Hence years of wet and
years II drought. Rain foods and storms are
not unprecedented" though it pleases some
young engineer whose work has been destroyed
to report 50. Floods and storms are part Of
the economy of nature, and ought to be studied,
foreseen, and provided for as, if any engineer
ing work can be made safe by a second work,
it ought to have been made safe by the first
work, aud so have prevented the loss Of time
aud the money wasted in restoration.
In q country 80 compact, so thickly peopled,
and so wealthy as England now is, the floods
we suffer from, being the result of former
errors, mal-arrangements, anu -1"ot,
are simply disgraceful. In -he ~.
of our civilization, when population 10. 81
land of little value, and theX neither4oads
nor steam power, water Mills were useful but
now many Of them are and have long heen an
injury and a nuisance. kRjyeGs and streams are
damned and blocked whIeh35Ught to be free,
and hundreds of thousands j acres of land. now
worth vastly more tlaa = < old mills, are per-
manently w~aterlogged sad occasionally flooded.
Abuse of rivers as our trade has increased has
increased also, until at present it would fill q
long catalogue to describe all the modes of a.
buSe practised. The evils, mischief. and
losses are national; the remedy must be
imperial. Entire river areas must be- dealt
with irrespective Of county or Narisb
boundaries, and private rights must be-
made subseryient to the general veal. There
is probably more wealth on the banks of the
1hdlheS IMAM OH any DINER llVer Ia the world
(and compared with some it is a mere rivuletl.
but look at the present state of the Thames
through past and oontinue1x eject. If il now
when flooded, one vast pestifer0uar swamp. In
Holland and IN our Fen districts the Inhabitants
prevent flooding and even keep out the seas.
The estuary Of the Thames has been embarked
from a time prehistoric, and yet the upper ans.
richer portions of the valley are allowed to be
disgracefully flooded. TIE river has ar Ioop
been embarked through the metropolis. Tie
valley above viii no doubt some day also be
dealt with. We are tod by those who do not
understand the question that foods ara moro
common and more violent now than formerIv-
that land draining shoots the surface water
down more rapidly. Land drains do nothing
of the sort but, if anything, for a time retard
the discharge of food water, just in proportion
as the drained land absorbes the first rain.
Floods are the effect Of continuous rain-so
continued that water fows off water, and the I'm.
drained surfaces and the drained surfaces then
act allke-the subsoil must be saturated up to
the surface, so that the continued heavy rain
must flow down to choke the neglected and abus.
ed rivers aud food the valleys. MAKE reseryoirs''
is advice in one form. Make reservoirs. GER.
tainlv, so far as may be necessary, for domestic
uses and for trade purposes but making reser.
voirs will go a short way to preventing damage
from rain-storm river foods. To prevent
flooding there must be a free course provided
for all excessive falls of rain, or mischief will
enSue. A stream which is apparently dried up
for months 10 q year can, in a few days, become
IL a. ~. ~