Chambers's Journal of Popular Literature, Science, and Art, No. 708

This was Tuesday, and I wanted to make sure of two clear days.

'I will contrive to run down before that, if you wish it, Mary.'

'No; I too have much to do. Do not come before Friday.'

'Very well. You will tell me then which day you have decided upon, since you will not say now.'

I had waived the decision as to which day the wedding was to take place; and I did so again, merely repeating 'Friday.'

'All right; take care of yourself; and be sure to have the hand seen to.' He was stooping down to give me the customary kiss before crossing the stile; but I took his two hands in mine, and looked up into his face, I think as calmly and steadily as I had prayed for strength to do.

'God bless you, Philip.' Then I put my arms about his neck, lifted up my face to his, and kissed him. 'Good-bye, dear Philip.'

I saw an expression of surprise, a slight doubt and hesitation in his eyes. He had not found me so demonstrative as this before, and was for the moment puzzled to account for it. But I contrived to get up a smile, which I think satisfied him. Then with a last wrench, I turned away, hearing as though from another world his answering 'Good-bye' as he vaulted the stile.

After that, the rest would be easy. I allowed myself one hour in the woods – not for the indulgence of regret – I knew too well the danger of that – but for recovery, and got back to the cottage in time for our early dinner. Moreover, I forced myself to eat, knowing that I should require all the strength I could get; and delighted dear kind old Mrs Tipper's heart by asking for a glass of wine.

It was a terrible ordeal, sitting there under their tender watchful eyes; but I got through it tolerably I think. Afterwards, I told them that I wanted to catch the three o'clock up-train, adding a purposely indefinite remark about having some arrangements to make in town.

'Is Mr Dallas going to meet you, my dear?' asked Mrs Tipper anxiously.

'No; I am going on a woman's errand,' I replied, with a sad little half-smile at the thought of what their surprise would be if they could know how very literally I was speaking.

'Must you go to-day? – may not I go with you, dear Mary?' pleaded Lilian. 'You are looking so pale and unlike yourself; I do not like the idea of your going alone.'

'I should fancy that there was something really the matter with me, if I could not go alone so short a distance as that, dearie,' I lightly replied. 'I think I will allow my age to protect me.'

She drew nearer to me, looking at me in the nervous, half-afraid way she so frequently did of late, as she laid her hand upon my arm.

'I wish you would not talk like that – dear Mary, why do you?'

I was not strong enough to bear much in this way; so replied with an attempt at a jest, which made her shrink away again. I daresay my jests were flavourless enough, and in strange contrast to my looks.

Mrs Tipper's silent, anxious watchfulness was even harder to bear than Lilian's tender love. It was not my journey to town which puzzled them – I saw that they imagined I was intent upon preparing some little pleasant surprise for them at my wedding – but the change they saw in me, which no amount of diplomacy could hide.

How thankful I was, when I at length made my escape to my own room; but I was not allowed to go alone. I had to bear Lilian's loving attendance whilst I was putting on my bonnet and cloak. Indeed, she lingered by my side until I had got half-way down the lane.

'You will not be very late, Mary?'

'No, dearie; I think not – I hope not.'

'We shall be longing to see you back.'

'And you must not be surprised if I return in a very conceited frame of mind, after being made so much of,' I lightly replied.

'Only come back yourself,' she murmured, giving me a last kiss as she turned away.

Dear Lilian, did she in truth guess something of what the lightness cost me? I knew that I did not deceive her wholly. Although she might be in some doubt as to the cause, I did not succeed in hiding the effects from her.

I arrived at the London terminus about four o'clock, and took a cab, directing the man to drive to a West-end street facing St James's Park. My errand was to one of the largest mansions there, which at any other time I should have considered it required some nerve to approach in a way so humble. I could quite understand the cabman's hesitating inquiry as to whether I wished to be driven to the principal entrance. Probably I did not appear to him quite up to the standard of the housekeeper's room. Fortunately I was not able to give a thought to my appearance. Had I been visiting the Queen, I should have thought of her only as a fellow-woman, in my deep absorption.

Three hours later I was taken back to the railway station in a luxurious carriage, borne swiftly along by spirited horses; a slight, refined, delicate-looking woman, with earnest thoughtful eyes, and attired almost as simply as myself, was sitting by my side with my hand in hers, as we now and again touched upon the subject which occupied our thoughts.

I had found a friend in my time of need, and such a one as I had not dared to hope for. But this in due time. We parted with just a steady look and grasp of the hand.

'To-morrow?'

'Yes; between six and seven.'

I returned to the cottage, certainly not looking worse than when I had quitted it, and was received with a welcome which made me almost lose courage again. Fortunately it was very nearly our usual time for retiring. Fortunately too I had much to do, and it had to be done in the small-hours of the night, so that I had no time to give to the indulgence of my feelings when I was left alone in my room. First turning out the contents of my drawers and boxes, I separated from them a few things which were absolutely needful for my purpose. One dress and cloak and bonnet were all that I should require, besides a small supply of under-clothing. The latter I put into a small trunk which Becky could easily carry, and then replaced the other things in the drawers again, arranging and ticketing them in orderly methodical fashion as I wished them by-and-by to be distributed. If 'Tom' should in course of time prove more appreciative of Becky – which in consequence of a hint I had received from Lydia, I did not despair of so much as she did – I pleased myself with the idea that the contents of certain drawers would make a very respectable outfit for her. The plain gray silk dress which I had purchased for my own wedding would not be too fine for hers. In a note placed on the top of the things, I begged Mrs Tipper to give them to Becky when the right time came. Afterwards I took out the little collection of my dear mother's jewellery. It was really a much better one than I had believed it to be. Indeed I had never before examined the contents of the packet. When it appeared probable that the jewels would have to be sold, I had avoided looking at them; shrinking painfully from the idea of calculating upon the money value of my mother's only legacy to me; and perhaps also in my time of need a little afraid of being tempted by the knowledge of its worth. One diamond ring, a large single stone, which even I could tell was of some value, I put on the finger of my left hand, which would never wear another now. That was all I would keep. I then put aside a pretty ruby brooch for my dear old friend Mrs Tipper; and after some hesitation about making a little offering to Philip, I satisfied myself with selecting a valuable antique ring which had belonged to my father, and writing a line begging Lilian to give it to him with the love of his sister Mary. The rest – I was quite proud of the quantity now – I packed up and addressed to the care of Mrs Tipper – my gift to my dear Lilian on her wedding-day.

SUBMARINE CABLES

WORKING

The working and maintenance of the existing telegraph lines employ a vast number of people taken all together; but it is surprising how few hands are necessary for the working of any single line or system. This is especially so in the case of submarine cables, where, when the cable continues sound, it is not necessary to support a staff for surveillance and repairs. Half-a-dozen stations several hundred miles apart, and half-a-dozen men at each, are sufficient to carry the news from one end of a continent to the other.

Without enumerating the telegraph systems that now exist, it may suffice to say that the British Isles are connected by submarine cables with nearly every quarter of the globe, and that their number is still increasing.

A telegraph station abroad, no matter in what Company or country, presents nearly the same characteristics wherever found. The more remote the place, the more primitive may be the arrangements; but the work is the same, the men are about the same, and the instruments almost invariably so. There is the superintendent; and under him the clerk in charge, his right-hand man, who oversees the clerks or operators at their work of sending and receiving messages. Then, besides these, and partly independent of them, there is the electrician, a member of the scientific as distinguished from the operating staff of the Company, whose duties are to take periodical tests of the cable and land-lines, to report on their condition, and to keep the instruments in proper working order. Under all these, there is generally the messenger and battery-man, who may be called the stoker of the electrical engine, and who, besides, does the odd work of the establishment.

The station itself generally consists of the superintendent's office or bureau; the instrument-room, where the messages are sent and received; the battery-room, generally under ground; and the sleeping-quarters of the clerks. Occasionally the electrician and clerk in charge have separate working-rooms; and a smoking-room, with perhaps a billiard-table and home newspapers, are added for the convenience of all. Life passes quietly and uneventfully at these stations, except when something goes wrong with the instruments or the cable, and then the electrician has his period of anxiety and trouble; while the operators, on the other hand, find their occupation at a temporary standstill.

To understand the working of a submarine cable and the actual process of sending a message, it is necessary to figure in imagination the several parts of the electric circuit, made up of the battery, the instruments, the cable, and the earth itself; and to remember that for a current of electricity to flow through any part of the circuit it is necessary that the whole circuit should be complete. Starting then from the battery, which is the source of the electric current, we have the cable joined to it by means of a key or sending instrument, which by the working of a short up-and-down lever can connect or disconnect the conductor of the cable to a particular pole of the battery, the other pole of the battery being the while connected to the earth. The cable then takes us to the distant station. Here the conductor is connected to the receiving instrument, or instrument for making the signals indicating the message, and through the receiving instrument it is connected to the earth. The electric circuit is thus rendered complete. The current passes from one pole of the battery by means of the key into the cable, through the cable to the instrument at the other end, and thence to the earth; and inasmuch as the other pole of the battery is at the same time connected to the earth at the first station, the conducting circuit is complete, for the earth, no matter what the intervening distance be, acts as an indispensable part of the circuit.

We have thus the two stations connected by a cable. At the station sending the message there is the battery, from which the current proceeds; the sending instrument, for letting the current into the cable, or stopping it; and the 'earth-plate,' or metal connection between one pole of the battery and the earth. At the station receiving the message there is the receiving instrument, and again the earth-plate, connecting the earth into circuit. These separate parts of the circuit, as we have already said, must be 'connected up,' as it is termed, so as to provide a complete conducting channel for the current to flow in from one pole of the battery to the distant place and back again (or virtually so) through the earth. Only at one place can the circuit be interrupted and the current consequently stopped – that is, at the key of the sending instrument. Here then the sending clerk sits, and by manipulating the lever of this key he 'makes and breaks' the circuit at will, and thereby controls the current. The regulated making and breaking of this connection is the basis of telegraphing, whether by submarine cable or by the ordinary land lines. Accordingly as the clerk maintains the circuit for a longer or a shorter time, so will the current give longer or shorter indications on the receiving instrument at the distant station: or again, according as the opposite poles of the battery are applied to the cable by the key, and the direction of the current consequently reversed in the cable, so will the indicated signals on the receiving instrument be of opposite kind. From the elementary short and long signals, or right and left signals, so obtained on the receiving instrument, a code of letters and words may be built up, and intelligible messages transmitted. The Morse Code is that universally adopted, and for the further information of our readers we here append it as it is usually written:

The numerals run:

For other accented letters, fraction signs, punctuation, and official directions as to the disposal of the message, there are other signs, but the above are the essentials of the Morse Code. The long and short signs represent the long and short signals of the receiving instrument, produced by the long and short contacts of the sending key with the battery. It will be seen that the letter A is rendered by a short signal followed by a long one; the letter B by a long signal followed by three separate short ones; and so on. Hence, in order to telegraph the letter A to his colleague at the distant end of the line, the clerk, by depressing the lever of the sending instrument, makes contact between the cable and the battery, first for a short time, and then for a longer time. The long and short signals are widely employed in overland telegraphy; but in submarine telegraphy a saving of time is effected by signals of opposite kind. Thus, if a left deflection, or deflection of the indicator to the left, signifies a 'dot' or short signal, a deflection to the right will signify a 'dash' or long signal. In this case the sending instrument or key has two levers, a right and left one, corresponding to the distinct signal which each produces. By depressing the left lever of the key, a pole of the battery is applied to the cable, which produces a left-hand signal on the receiving instrument at the distant station; and by depressing the right-hand lever, a right-hand signal is produced. Proper rests or intervals are permitted between the separate words, letters, and full stops of a message.

The battery in common use for submarine telegraphy is either the sawdust Daniell or the Leclanché. The Daniell consists of a plate of zinc and a plate of copper brought into contact with each other by sawdust saturated with a solution of sulphate of zinc; and crystals of sulphate of copper (bluestone) are packed round the copper plate, so as to dissolve there in the solution of sulphate of zinc. The zinc plate forms the negative pole of the battery, and the copper plate the positive pole. When these two poles are connected together by a wire or other conducting circuit, such as that made up of the cable and the earth, a current of electricity – the voltaic current – flows from one to the other, and always in one direction, namely, from the copper or positive pole to the zinc or negative pole. Hence it is that by applying the one pole or other to the cable and the other to earth through the earth-plate, the direction of the current in the cable is reversed and opposite signals produced.

The earth-plate is usually a copper plate several feet square, sunk deep into the moist subsoil near the station, so as to make a good conducting contact with the mass of the earth.

The receiving instruments for working a submarine cable are different from those used in working land-lines. Inasmuch as the current travels full strength, like a bullet, through a land-line, and in the form of an undulation or wave through a cable, so is it necessary to have different kinds of receiving instruments for each. In a land-line powerful currents can be used with impunity, and these can be made, by means of electro-magnetism, to move comparatively heavy pieces of mechanism in giving signals. But in a cable the currents are prudently kept as low as possible, in case of damage to the insulator, and the receiving instrument must therefore be delicate. In land-lines the current passes in an instant, leaving the line clear for the next signal, so that the indications of the receiving instrument are abrupt and decided. But in a cable the electric current takes an appreciable time to flow from end to end, so that the separate signals in part coalesce, the beginning of one blending with the end of that preceding it, so that the signals become involved with each other. It is necessary, therefore, that time be allowed for each wave to clear itself of the cable before another wave is sent in, otherwise we would have the cable as it were choked with the message. A continuous current of electricity may be said to be flowing through it, and the ripples on the surface are the separate signals of the message. It is to take cognisance of these waves or ripples that the receiving instrument for cable-work must be designed; and as the quicker the message is sent into the cable the smaller these ripples will be, the more delicate should be the instrument.

There are only two instruments in use on long cables, and both are the invention of Sir William Thomson, the distinguished Glasgow physicist and electrician. The mirror galvanometer has been already described in this Journal in a paper on the manufacture of submarine cables; and the 'mirror' or 'speaker,' the commonest of these receiving instruments, is but a modified form of the mirror galvanometer. It consists of a hollow coil of silk-covered wire, in the heart of which a tiny mirror, with several small magnets cemented to its back, is suspended by a single thread of floss-silk fibre. A beam of light from a lamp is thrown upon the mirror, and reflected from it on to a white screen, across which a vertical zero-line is drawn. When no current is passing through the coil, the reflected beam of light which makes an illuminated spot or gleam on the screen, remains steady at the zero-line. But when a current passes through the coil, the magnets in its heart are moved and the mirror with them, so that the beam of light is thrown off at a different angle, and the spot of light is seen to move from the zero-line along the screen to right or to left of the zero-line according as the current is made or reversed in the coil; so that as the key is manipulated at the sending station, so are right or left signals received by the clerk who sits watching the movements of this spot of light, and interpreting them to his fellow-clerk, who writes them down. In the form of instrument here described, and also in the other receiving instrument for submarine work, the zero is not fixed but movable. The vertical line on the screen is only the nominal zero. The continuous current underlying the ripples which form the message, deflects the spot from the zero-line; but this slow deflection can be disregarded by the clerk, for over and above it there are smaller quicker movements of the spot to right and left corresponding to the ripples, and these are the proper signals of the message. It requires long practice to make a good 'mirror' clerk, one who can follow the gleam with his eye through all its quick and intricate motions, and distinguish between those due to the shifting zero and those due to the various signals sent. Even this compound-ripple difficulty, however, is now got rid of by the use of an apparatus called a 'condenser,' the effects of which are that continuous currents are neutralised, and the pulsations of the signals sent are alone seen in the movements of the light upon the scale.

The other instrument is the siphon recorder, which permanently records in ink the signals which the 'mirror' only shews transiently. The principle of the siphon recorder is the converse of that of the mirror. In the mirror there is a large fixed coil and a light suspended magnet. In the siphon recorder there is a large fixed magnet and a light suspended coil. When the current passes through this coil, the latter moves much in the same way as the magnet moves in the 'mirror;' that is, it rocks to right or left according as the current flows. This rocking motion is communicated, by a system of levers and fibres, to a very fine glass capillary siphon, which dips into an ink-bottle and draws off ink upon a strip of running paper. The ink is highly electrified, so as to rush through the siphon and out upon the paper, marking a fine line upon it as it runs. When no current passes in the coil, this zero-line is straight; but when currents are passing, the line becomes zigzag and wavy; and the right and left waves across the paper constitute the message. Both of these instruments are very beautiful and ingenious applications of well-known electric, optical, and mechanical principles. The great merit of the recorder is that if a false signal is accidentally made by the sending clerk, the whole word need not always be lost by the receiving clerk, but may be made out from the rest of the word written down. Thus much repetition of messages is saved. There is some advantage too in having a written message for purposes of after reference.

A singularly ingenious system of telegraphy, termed the duplex, has recently been extended to long submarine cables, and is likely to become of general, if not universal application. It is effected by constructing an artificial line, in this case representing an artificial cable, which shall have the same influences on the current that the actual cable has. The signalling current from the battery is then split up at each station between the actual cable and the artificial cable, so that half flows into one and half into the other. And there is placed a receiving instrument in such a way between these two halves of the current that they exactly counterbalance each other's effect upon it; and so long as sending is going on from a station, the receiving instrument at that station is undisturbed. But the sending currents from the other station have the power to disturb this balance and cause signals to be made. Thus then, while the sending at a station does not affect the receiving instrument in connection with the cable there, the currents sent from the distant station cause it to mark the signals. Each station is thus enabled to send a message and receive one at the same time; and this is what is called duplex or double telegraphy.

In ordinary telegraphy, one station is receiving while the other is sending; but in duplex working, both stations are sending together and receiving together, so that there is little or no delay in the traffic, and the carrying power of a busy cable is practically doubled.

In case of accident to the cables each Company maintains a repairing-ship ready to go to sea at shortest notice. Some 'faults' are of a nature not seriously to interfere with the working of a cable; but it cannot be expected that they will remain always in the same comparatively harmless state. When a flaw occurs in the insulator it tends to enlarge itself, and more of the current escapes to the sea, until so much escapes that the current which reaches the distant station is too feeble to work the instruments there. All traffic therefore ceases. The electrician's tests having localised the fault so many miles from shore, the repairing-ship proceeds to the spot. Here she lowers her grapnel a mile or two on one side or other of the supposed line of the cable, and when enough rope has been let out, she steers very slowly under steam, or drifts with the tide across the cable's track. The grapnel is simply a great iron hook, one approved form being like a compound fish-hook, with five or six flukes starting from the shank. A weight of chain drags behind it, to keep it well down on the bottom. The rope, which is generally of wire and yarn, passes under a dynamometer, which indicates its tension, and thence to the steam winch used for hauling in. Often the grapnel catches in rocks, or mud, and gives rise to false hope of the cable having been found. The ship is brought to, and hauling in commences; but soon the obstruction 'gives,' or the grapnel itself breaks, and the true nature of the 'catch' is found out. When the cable is hooked, the greatest skill and care are needed, especially when the ship's head lifts with the waves, to bring up the bight carefully without breaking the cable. When brought to the surface the cable is cut, and each end is brought on board in turn and tested. The fault, as we have previously shewn with the paying-out ship, may prove to be but a few miles distant. The sound end is thereupon buoyed, and the ship proceeds to pick up or haul in the faulty end until it is thought the fault must have been picked up. The electrician then cuts off the piece which contains the fault, and then he has only to join on a sound piece of cable in its place, and lay it back to the end that was buoyed, so filling up the gap. But if it should not contain the fault, the tests are again applied, until finally the fault is detected and cut out. Repairing is arduous and trying work; now giving rise to hopes, now crushing them, and anon deferring them. A great responsibility rests on those who undertake them, as the gain or loss of a week or two may represent an enormous sum of money to the Company.

CROSS-PURPOSES