The true northerner. [volume] (Paw Paw, Mich.) 1855-1920, 1872-01-26
EJoatjng BreakWaterS.

W
recommended in paper read before
the London Society OF Engineers. 1t is
said that they can be built at one-tenth
of the cost Of solid structures, and can
he rendered no less durable. If so, a
vast gain may be effected by introducing
them. II looks doubtful at first sight,
whether any edifce, not resting on the
bottom, could have the permanency of,
for example, Trajan's outer mole at
Civita Vecchia, or the modern structures
of Cherbourg, Plymouth, and Delaware
Bay. But on the other hand floating
breakwaters may be possible where solid
ones would be out Of the question.
There are places where such barriers are
highly desirable, but where, from the
depth of water, the character of the
bottom, or the periodic violence Of the
sea, they cannot be employed. The ex-
pensive failures at Cherbourg beginning
from the time of Louis XVI, have
taught engineers useful lesson, and
the result, such as it is, gained at last,
was founded on successive ruins that
had gone before.
The subject of breakwaters, important
to most marine nations, is especially so
} to the United States. Considering the
ltHGtH vi OuI COdSp iiiiCo, WIG
of harbors is manifestly deficient. Be-
fore the Delaware work was constructed,
there was no shelter for ship caught
off the coast in an easterly gale in the
whole stretch from New York Harbor
to Chesapeake Bay; and there are many
long spaces between Portland and Gal
weston similarly unprovided for. Again,
on the great lakes, the same want is
i 81
such structures as exist at Buffalo,
Cleveland and Chicago will have to be
largely multiplied. A glance at the
list of disasters on these vast inland
seas will afford some idea of the prob
able saving in life and property, had
there been enough harbors OF refuge for
vessels. The main difficulty, in most
instances, about breakwaters, is their
enormous cost. If, then, floating works
can be had for tenth of the ordinary
outlay, as is now stated by Mr. Cargill,
and affirmed by other engineers, it is
important that we should know and
profit Dy it.
The principle of the proposed float
ing breakwater, like that OF many other
of our most valuable inventions, has
been suggested by watching the opera
tons Of nature. 1t has been observed,
particularly in the gulf stream, that in
places where chance collections have
been formed of sea weed, reeds. and
the like, the force of the impinging
waves has been more or less broken
thereby The influence of those waves,
it has been seen, does not extend many
feet below the level surface OF the sea.
Hence it is thought that their force can
be broken, if not entirely resisted, by
ad ing system like the form Of nat
ura. breakwater made by stray sticks
and seaweed. Mr.. Cargill, therefore,
does not propose solid and immovable
opposing obstacle. He recommends a
structure composed of iron lattice frame
work, with vertical or inclined plates
let in at intervals, by which means
"the wives would be gradually dlsin-
tegrated and strained, as it were, OF all
their violence, until they reached the
landward side of the barrier, In state
of complete quiescence." 1t is sad by
men OF science that there would not be
the least difficulty in mooring such q
breakwater, since the perforated and
non.resisting characteristic would pre-
vent any heavy strain upon the cables
when anchored. We presume that part
of the framework would be cast hollow,
in order to obtain the needful buoyancy;
and certainly, if securely made fast,
such a barrier would seem to be as in
destructible as it is claimed it would be
effectual.
Mr.. Cargill's plan has one great point
in its favor, which is that trial of it
could be made on a small scale and at
little cost. The requisite material
could be had for moderate price, and,
for that matter, need not be wasted
even i'll case of failure. 1t was appa-
rently necessary for iron manufacture
to reach its present advanced stage
to render such scheme practicable,
since only in that metal can be secured
the essential combination of lightness
and strength. Experiments will soon
be made in England that will prove
CONCLUSIVE one way or the other, and, il
the results are prosperous, there is lit
tie doubt that floating breakwaters will
speedily come into use in both Europe
and America-NeD York Times.