CHAPTER EIGHT.

LAYING THE CABLE--"FAULTS" AND FAULT-FINDING--ANXIETIES, ACCIDENTS, AND

OTHER MATTERS.

Come with us now, good reader, to another and very different scene--out

upon the boundless sea. The great Atlantic is asleep, but his breast

heaves gently and slowly like that of a profound sleeper.

The Great Eastern looks like an island on the water--steady as a rock,

obedient only to the rise and fall of the ocean swell, as she glides

along at the rate of six knots an hour. All is going well. The

complicated-looking paying-out machinery revolves smoothly; the

thread-like cable passes over the stern, and down into the deep with the

utmost regularity.

The shore-end of the cable--twenty-seven miles in length, and much

thicker than the deep-sea portion--had been laid at Valentia, on the

22nd of July, amid prayer and praise, speech-making, and much

enthusiasm, on the part of operators and spectators. On the 23rd, the

end of the shore cable was spliced to that of the main cable, and the

voyage had begun.

The first night had passed quietly, and upwards of eighty miles of the

cable had gone out of the after-tank, over the big ship's stern, and

down to its ocean-bed, when Robin Wright--unable to sleep--quietly

slipped into his clothes, and went on deck. It was drawing near to

dawn. A knot of electricians and others were chatting in subdued tones

about the one subject that filled the minds of all in the ship.

"What! unable to sleep, like the rest of us?" said Ebenezer Smith,

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 which we want to send our message. D'you understand?"

"I think I do, sir; but _how_ is the exact amount of resistance tested?"

Mr Smith smiled as he looked at the earnest face of his young

questioner.

"My boy," said he, "you would require a more fully educated mind to

understand the answer to that question. The subtleties of electrical

science cannot be explained in a brief conversation. You'll have to

study and apply to books for full light on that subject. Nevertheless,

although I cannot carry you _into_ the subject just now, I can tell you

something _about_ it. You remember the testing-room which I showed you

yesterday--the darkened room between the captain's state-room and the

entrance to the grand saloon?"

"Yes, sir, I remember it well," responded Robin,--"the room into which

the conducting-wires from the ends of the cable are led to the

testing-tables, on which are the curious-looking galvanometers and other

testing machines."

"Just so," returned Smith, pleased with his pupil's aptitude. "Well, on

that table stands Professor Thomson's delicate and wonderful

galvanometer. On that instrument a ray of light, reflected from a tiny

mirror suspended to a magnet, travels along a scale and indicates the

resistance to the passage of the current along the cable by the

deflection of the magnet, which is marked by the course of this speck of

light. Now, d'you understand that, Robin?"

"I--I'm afraid not quite, sir."

"Well, no matter," rejoined Smith, with a laugh.

"At all events you can understand that if that speck of light keeps

within bounds--on its index--all is going well, but if it travels beyond

the index--bolts out of bounds--an escape of the electric current is

taking place somewhere in the cable, or what we call a _fault_ has

occurred."

"Ah, indeed," exclaimed Robin, casting a serious look at the cable as it

rose from the after-tank, ran smoothly over its line of conducting

wheels, dropped over the stern of the ship and glided into the sea like

an an endless snake of stealthy habits. "And what," he added, with a

sudden look of awe, "if the cable should break?"

"Why, it would go to the bottom, of course," replied Smith, "and several

hearts would break along with it. You see these two gentlemen

conversing near the companion-hatch?"

"Yes."

"One is the chief of the electricians; the other the chief of the

engineers. Their hearts would probably break, for their position is

awfully responsible. Then my heart would break, I know, for I feel it

swelling at the horrible suggestion; and your heart would break, Robin,

I think, for you are a sympathetic donkey, and couldn't help yourself.

Then you see that stout man on the bridge--that's Captain Anderson--

well, _his_ heart would--no--perhaps it wouldn't, for he's a sailor, and

you know a sailor's heart is too tough to break, but it would get a

pretty stiff wrench. And you see that gentleman looking at the

paying-out gear so earnestly?"

"What--Cyrus Field?" said Robin.

"Yes; well, his heart and the Atlantic Cable are united, so as a matter

of course the two would snap together."

Now, while Smith and his young assistant were conversing thus

facetio-scientifically, the electricians on duty in the testing-room

were watching with silent intensity the indications on their

instruments. Suddenly, at 3:15 a.m., when exactly eighty-four miles of

cable had been laid out, he who observed the galvanometer saw the speck

of light glide to the end of the scale, and vanish!

If a speck of fire had been seen to glide through the key-hole of the

powder-magazine it could scarcely have created greater consternation

than did the disappearance of that light! The commotion in the

testing-room spread instantly to every part of the ship; the whole staff

of electricians was at once roused, and soon afterwards the engines of

the Great Eastern were slowed and stopped, while, with bated breath and

anxious looks, men whispered to each other that there was "a fault in

the cable."

A fault! If the cable had committed a mortal sin they could scarcely

have looked more horrified. Nevertheless there was ground for anxiety,

for this fault, as in moral faults, indicated something that _might_ end

in destruction.

After testing the cable for some time by signalling to the shore,

Monsieur de Sauty concluded that the fault was of a serious character,

and orders were at once given to prepare the picking-up apparatus at the

bow for the purpose of drawing the cable back into the ship until the

defective portion should be reached and cut out.

"O _what_ a pity!" sighed Robin, when he understood what was going to be

done, and the feeling, if not the words, was shared by every one on

board with more or less intelligence and intensity; but there were

veterans of submarine telegraphy who spoke encouragingly and treated the

incident as a comparatively small matter.

Two men-of-war, the Terrible and the Sphinx, had been appointed to

accompany and aid the Great Eastern on her important mission. A gun was

fired, and signals were made, to acquaint these with what had occurred

while the fires were being got up in the boilers of the picking-up

machinery.

Electricians as well as doctors differ, it would seem, among themselves,

for despite their skill and experience there was great difference of

opinion in the minds of those on board the big ship as to the place

where the fault lay. Some thought it was near the shore, and probably

at the splice of the shore-end with the main cable. Others calculated,

from the indications given by the tests, that it was perhaps twenty or

forty or sixty miles astern. One of the scientific gentlemen held that

it was not very far from the ship, while another gentleman, who was said

to be much experienced in "fault"-finding, asserted that it was not more

than nine or ten miles astern.

While the doctors were thus differing, the practical engineers were busy

making the needful preparations for picking-up--an operation involving

great risk of breaking the cable, and requiring the utmost delicacy of

treatment, as may be easily understood, for, while the cable is being

payed out the strain on it is comparatively small, whereas when it is

being picked up, there is not only the extra strain caused by stoppage,

and afterwards by hauling in, but there is the risk of sudden risings of

the ship's stern on the ocean swell, which might at any moment snap the

thin line like a piece of packthread.

The first difficulty and the great danger was to pass the cable from the

stern to the bow, and to turn the ship round, so as to enable them to

steam up to the cable while hauling it in. Iron chains were lashed

firmly to the cable at the stern, and secured to a wire-rope carried

round the outside of the ship to the picking-up apparatus at the bows.

The cable was down in 400 fathoms of water when the paying-out ceased,

and nice management was required to keep the ship steady, as she had now

no steerage-way; and oh! with what intense interest and curiosity and

wonder did Robin Wright regard the varied and wonderful mechanical

appliances, with which the whole affair was accomplished!

Then the cable was cut, and, with its shackles and chains, allowed to go

plump into the sea. Robin's heart and soul seemed to go along with it,

for, not expecting the event, he fancied it was lost for ever.

"Gone!" he exclaimed, with a look of horror.

"Not quite," said Jim Slagg, who stood at Robin's elbow regarding the

operations with a quiet look of intelligence. "Don't you see, Robin,

that a wire-rope fit a'most to hold the big ship herself is holdin' on

to it."

"Of course; how stupid I am!" said Robin, with a great sigh of relief;

"I see it now, going round to the bows."

At first the rope was let run, to ease the strain while the ship swung

round; then it was brought in over the pulley at the bow, the paddles

moved, and the return towards Ireland was begun. The strain, although

great, was far from the breaking-point, but the speed was very slow--not

more than a mile an hour being considered safe in the process of

picking-up.

"Patience, Robin," observed Mr Smith, as he passed on his way to the

cabin, "is a virtue much needed in the laying of cables. We have now

commenced a voyage at the rate of one mile an hour, which will not

terminate till we get back to Owld Ireland, unless we find the fault."

Patience, however, was not destined to be so severely tried. All that

day and all night the slow process went on. Meanwhile--as the cable was

not absolutely unworkable, despite the fault--the chief engineer, Mr

Canning, sent a message to Mr Glass in Ireland, asking him to send out

the Hawk steamer, in order that he might return in her to search for the

defect in the shore-end of the cable, for if that were found he purposed

sacrificing the eighty odd miles already laid down, making a new splice

with the shore-end, and starting afresh. A reply was received from Mr

Glass, saying that the Hawk would be sent out immediately.

Accordingly, about daybreak of the 25th the Hawk appeared, but her

services were not required, for, about nine that morning, when the cable

was coming slowly in and being carefully examined foot by foot--nay,

inch by inch--the fault was discovered, and joy took the place of

anxiety. Ten and a quarter miles of cable had been picked up when the

fault came inboard, and a strange unaccountable fault it turned out to

be--namely, a small piece of wire which had been forced through the

covering of the cable into the gutta-percha so as to injure, but not

quite to destroy, the insulation. How such a piece of wire could have

got into the tank was a mystery, but the general impression was that it

had been carried there by accident and forced into the coil by the

pressure of the paying-out machinery as the cable flew through the

jockey-wheels.

Signals were at once made to the fleet that the enemy had been

discovered. Congratulatory signals were returned. The fault was cut

out and a new splice made. The Hawk was sent home again. The big

ship's bow was turned once more to the west, and the rattling of the

machinery, as the restored and revived cable passed over the stern, went

merrily as a marriage bell.

The detention had been only about twelve hours; the great work was going

on again as favourably as before the mishap occurred, and about half a

mile had been payed out, when--blackness of despair--the electric

current suddenly ceased, and communication with the shore was ended

altogether.

The Battery and the Boiler: Adventures in Laying of Submarine Electric Cables · 第 17 / 74 题