for when all completed, it formed a coil thirty
feet in diameter on the outside, fifteen on the
inside, five feet high, and weighing a hundred
and eighty tons. A great work was the
manufacture of this cable. In the first place,
at the Gutta Percha Company's works, about
a hundred miles of copper wire, in fair equal
lengths, were coated and coated again with
this singular gum; and then they were
transferred to a cable-making factory at Wapping.
The four coated wires were grouped, and
were bound round with hempen yarn steeped
in a solution of tar and tallow, by the aid of
a machine. This rope, if it may be so called,
was passed vertically up a tube, around
which were ten large bobbins filled with
galvanised iron wire; and while the rope was
travelling upward, and the bobbins were
busily rotating on their axes, the wire,
unwinding from the bobbins, coiled itself in a
hard twist around the rope, compassing the
hemp and the gutta percha closely, without
allowing the all-important copper telegraphic
wires in the centre to come in contact one with
another.

And so again, in eighteen hundred and
fifty-three, when the still more remarkable
"line of thought" was prepared to stretch
from England to Belgium. The Calais cable
has four copper telegraphic wires, but the
Belgian cable has six; the Calais cable is
encircled by ten twisted wires, but the .Bel-
gian cable is encircled by twelve; the length
of the former is twenty-four miles, but of the
latter the length is upwards of seventy miles;
of the former the weight is a hundred and
eighty tons, but of the latter not much less
than five hundred tons. For aught that is
yet known, the wire-drawers and wire-twisters
could do their part towards the construction
of a submarine telegraph across the very
Atlantic itself, if the difficulties in other
directions can be surmounted. The internal
copper wires for these and other telegraphs
are sometimes coated with gutta percha in a
singular way. The engineers who, about six
years ago, laid down four or five hundred
miles of telegraph from Berlin to Frankfort-
on-the-Main, thus coated their wire; they
had a box or small chamber with eight small
holes on one side, and eight larger holes on
the opposite; they put eight copper wires in
at the small holes and out again at the larger;
they forced in hot gutta percha by a piston,
and forced out the eight wires, each with a
close wrapper of gutta percha.

He who would know all the forms into
which wire is now twisted, and woven, and
linked, must rise betimes and give a long
day to it. He must look at the wire-netting
fences, for excluding hares and rabbits from
gardens, for enclosing poultry-yards and
pheasantries, and for guarding tender young plants.
He must see how this wire is galvanised for
some purposes, to render it durable without
painting or tarring. He must know
something about the very strong wire-netting for
confining sheep and dogs; and the various
kinds used for aviaries, trellis-work, flower-
training, window-guards, and sky-lights; and
wire-fencing of a more ornate character for
gardens and pleasure grounds; and wire-
pheasantries, something like large bird cages;
and pheasant or hen-coops; and wire garden-
borders, around flower-beds and parterres;
and wire plant-guards, encircling the young
plants and shielding them from all intruders;
and stronger tree-guards made to open at the
sides. There are, too, wire-fences, with or
without wire-netting attached; wire arbours,
niches, and summer-houses; wire umbrellas
or canopies, around and over which roses
may cluster in the middle of a flower-bed;
wire flower-stands, for conservatory, or
greenhouse, or hall; wire chairs and garden seats,
wire gauze blinds; wire bird cages; wire
fire guards and fenders; wire lamps and
lanterns; wire meat covers and meat safes;
wire lattice for bookcases and windows; wire
sieves and strainers; wire cloth for flax-
dressing and paper-making. The wire-gauze
is a pretty material, woven in a loom as if it
were some fibrous material. We have seen
brass wire-gauze so exquisitely fine as to have
sixty-seven thousand meshes in a square
inch.

Our readers are not unfamiliar with the
sad narratives of coal-pit explosions, Davy
lamps, and fire-damp. Yet we may spare
a dozen lines or so, to explain how it is
that iron wire plays so important a part in
the clever but neglected contrivances for
lessening such disasters. In the great
coalfields of our northern counties, the seams of
coal give forth large quantities of carburetted
hydrogen, called by the miners fire-damp.
This fire-damp mingles readily with common
air, and a certain ratio between the two
produces an explosive compound; and when a
light approaches such a compound, an explosion
ensues which produces the devastation
so often recorded in the newspapers. Even
while we now write, public attention is
directed to a dread calamity whereby nearly
a hundred human creatures in one pit have
been destroyed by an explosion of fire-
damp.  It was to guard against these awful
scenes that Sir Humphrey Davy invented his
beautiful safety lamp. If a fine gauze be
woven of iron wire, the iron cools a flame too
much to allow it to pass through the gauze.
Davy, therefore, said:—" if the miner's lamp
be surrounded by iron-wire gauze, and the
fire-damp passes through and becomes
kindled, the flame cannot come out again,
but becomes cooled and extinguished, and
air-ignited gas passes out instead, thereby
preventing the fire-damp in the rest of the
mine from becoming ignited." He was right.
In Dr. Clanny's improvement on Davy's lamp,
the wire gauze has about thirteen hundred
meshes in the square inch. The principle is
sound and beautiful; but the practice is
sadly overlaid with negligence and blunder.