serve to stretch out the wire by rolling it
round itself. It was a delicate operation, and required much care. The
iron, prepared previously in long thin rods, the ends of which were
sharpened with the file, having been introduced into the largest hole of
the drawplate, was drawn out by the beam which wound it round itself,
to a length of twenty-five or thirty feet, then unrolled, and the same
operation was performed successively through the holes of a less size.
Finally, the engineer obtained wires from forty to fifty feet long,
which could be easily fastened together and stretched over the distance
of five miles, which separated the corral from the bounds of Granite
House.

It did not take more than a few days to perform this work, and indeed
as soon as the machine had been commenced, Cyrus Harding left his
companions to follow the trade of wiredrawers, and occupied himself with
manufacturing his battery.

It was necessary to obtain a battery with a constant current. It is
known that the elements of modern batteries are generally composed of
retort coal, zinc, and copper. Copper was absolutely wanting to the
engineer, who, notwithstanding all his researches, had never been able
to find any trace of it in Lincoln Island, and was therefore obliged to
do without it. Retort coal, that is to say, the hard graphite which
is found in the retorts of gas manufactories, after the coal has
been dehydrogenized, could have been obtained, but it would have been
necessary to establish a special apparatus, involving great labor. As
to zinc, it may be remembered that the case found at Flotsam Point was
lined with this metal, which could not be better utilized than for this
purpose.

Cyrus Harding, after mature consideration, decided to manufacture a
very simple battery, resembling as nearly as possible that invented
by Becquerel in 1820, and in which zinc only is employed. The other
substances, azotic acid and potash, were all at his disposal.

The way in which the battery was composed was as follows, and the
results were to be attained by the reaction of acid and potash on each
other. A number of glass bottles were made and filled with azotic acid.
The engineer corked them by means of a stopper through which passed a
glass tube, bored at its lower extremity, and intended to be plunged
into the acid by means of a clay stopper secured by a rag. Into this
tube, through its upper extremity, he poured a solution of potash,
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