accosting Robin as he reached the deck.

"Yes, sir," said Robin, with a sleepy smile, "I've been thinking of the
cable so much that I took to dreaming about it when I fell asleep, and
it suddenly turned into the great sea-serpent, and choked me to such an
extent that I awoke, and then thought it better to get up and have a
look at it."

"Ah! my boy, you are not the only one whom the cable won't let sleep.
It will be well looked after during the voyage, for there are two sets
of electricians aboard--all of them uncommonly wide awake--one set
representing the Telegraph Construction and Maintenance Company, under
Monsieur de Sauty; the other set representing the Atlantic Telegraph
Company, under Mr Varley and Professor Thomson. The former are to test
the electrical state of the cable, and to keep up signals with the shore
every hour, night and day, during the voyage, while the latter are to
watch and report as to whether the cable fulfils her conditions, as
specified in the contract. So you see the smallest fault or hitch will
be observed at once."

"Do you mean, sir," asked Robin in surprise, "that telegraphing with the
shore is to be kept up continually _all_ the voyage!"

"Yes, my boy, I do," answered Smith. "The lengths of the cable in the
three tanks are joined up into one length, and telegraphing--for the
purpose of testing it--has been kept up with the shore without
intermission from the moment we left Ireland, and began to pay out. It
will be continued, if all goes well, until we land the other and in
Newfoundland. The tests are threefold,--first, for insulation, which,
as you know, means the soundness and perfection of the gutta-percha
covering that prevents the electricity from escaping from the wires,
through the sea, into the earth; secondly, for continuity, or the
unbroken condition of the conductor or copper core throughout its whole
length; and, thirdly, to determine the resistance of the conductor, by
which is meant its objection to carry our messages without vigorous
application of the spur in the form of increased electrical power in our
batteries. You see, Robin, every message sent to us from the shore, as
well as every message sent by us in reply, has to travel through the
entire length of the cable, namely about 2400 miles, and as every mile
of distance increases this unwillingness, or resistance, we have to
increase the electrical power in the batteries, in proportion to the
distance to whi