The Battery and the Boiler, Robert Michael Ballantyne [best book club books .TXT] 📗

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