ance to
Algiers, 520 miles, laid in 1860, and the other, laid only last year,
from Malta to Alexandria, 1,535 miles! All together the lines laid by
these manufacturers comprise a total of 3,739 miles; and though some
have been lying at the bottom of the sea and working for eight years,
each one of them is at this hour in as perfect condition as on the day
it was laid down, with the exception of the two short lines laid in
shallow water along the shore between Liverpool and Holyhead, 25 miles,
and from Prince Edward's Island to New Brunswick, 11 miles; the latter
of which was broken by a ship's anchor, and the former by the anchor
of the Royal Charter during the gale in which she was wrecked, both of
which can be easily repaired.

Where failures have occurred in submarine telegraphs, the causes are now
well understood and easily to be avoided. Thus with the first Atlantic
cable, its defects have all been carefully investigated by scientific
men, and may be easily guarded against. When this cable was in process
of manufacture in the factory of Messrs. Glass, Elliot, & Co., in
Greenwich, near London, it was coiled in four large vats, and there
left exposed, day after day, to the heat of a summer sun, which was
intensified by the tarred coating of the cable to one hundred and twenty
degrees. This went on, day after day, with the knowledge of the engineer
and electrician of the company, although the directors had given
explicit orders that sheds should be erected over the vats to prevent
the possibility of such an occurrence. As might have been foreseen, the
gutta-percha was melted, so that the conductor which it was desired to
insulate was so twisted by the coils that it was left quite bare in
numberless places, thus weakening, and eventually, when the cable
was submerged, destroying the insulation. The injury was partially
discovered before the cable was taken out of the factory at Greenwich,
and a length of about thirty miles was cut out and condemned. This,
however, did not wholly remedy the difficulty, for the defective
insulation became frequently and painfully apparent while the cable was
being submerged. Still further evidence of its imperfect condition was
afforded when it came to be cut up for charms and trinkets.

The first cable was, to a great extent, an experiment,--a leap in
the dark. Its material and construction were as good as the state of
knowledge at that time provided, and in many respects not unsuitabl