WATSON'S TELEGRAPH.

WHEN We consider that time is an element in all our undertakings, whether for duty, for profit, or for pleasure an element which of necessity more or less retards the attainment of our objects, we cannot fail to perceive that shortening the time requisite for any act, is in almost all cases an effect | to be desired. That there is a perception of this truth in the minds of all, every hour of every man's life furnishes some examples. Why does the husbandınan plough, instead of turning over the ground with a spade? Why does he water his land by a system of irrigation, instead of using vessels of water? Let all question themselves as to the motives by which their daily actions are prompted, and it will be found that a desire to save time is one of the most remarkable and extensive of these motives.

To trace the operation of time-saving inventions in manufactures or in locomotion, is wholly beyond our present purpose; but it is worthy of thought whether the cause of Civilization be not closely bound up with such inventions. Let us take one single class of instances, viz. speedy communication of intelligence. Now, whatever good we try to effect, whether the agents of that good be Christian missionaries, or any other class of the community, frequent and rapid intercourse from place to place greatly enhances the power of effecting it.

Benefits often cease to be benefits, unless conferred quickly advice and counsel, asked from a distant quarter, become valueless from the delay in their arrival : danger and peril, removable by prompt attention, often produce their full effects when time delays the arrival of aid; and poverty might sometimes be averted, could we know what is passing at a distant place, where, perhaps, friends are labouring in our favour. Leaving our readers to work out the idea here merely shadowed forth, we will proceed to give a rapid sketch of that branch of time-saving invention which relates to telegraphic communication.

When commerce was in its infancy, and war formed the chief employment of men, generals and leaders were wont to give signals, by which intelligence of some great event could be conveyed to a distant quarter. Fires raised on a hill were the principal of these signals. Such a custom as this seems to be alluded to in the 1st verse of the 6th chapter of Jeremiah: "O ye children of Benjamin, gather yourselves to flee out of the midst of Jerusalem, and blow the trumpet in Tekoa, and set up a sign of fire in Beth-haccerem: for evil appeareth out of the north, and great destruction." The Greek and Roman writers make frequent mention of signals; in some instances, formed of fires or other strong lights; and in other cases, sounds, emitted from large tubes or trumpets. After gunpowder was invented, the sound occasioned by its

explosion became available as a signal; and since then rockets have added to the store of sign-producing agents.

But all such are manifestly rude and inefficient. They can do nothing more than give a sign, the purport of which has been agreed on beforehand. Any precise information beyond this requires the aid of farther arrangements, such as the exhibition of the letters of the alphabet, chosen in such order as to produce words. Kessler, an old German writer, proposed to cut out characters in the bottom of a cask having a light placed within it, the characters being changed in succession, in order to express single words and whole sentences. Some time after this, Dr. Hooke proposed to provide thirty boards, some square, some triangular, some circular, &c., and to exhibit them either singly or together: a vocabulary was to be provided, whereby the precise meaning of any particular combination of boards was to be determined. M. Amontons, Mr. Lovell Edgeworth, and other ingenious men, from time to time proposed improved forms of telegraph; but nothing definite was put into practice until the year 1794, when the French army being at Lisleit was deemed desirable to keep up rapid communication between the generals and the government at Paris. Stations were fixed, at intervals of three or four leagues, from Paris to Lisle. Each station occupied three persons; one to read, by the aid of a telescope, the signal made at the adjoining station; another to work the telegraph; and the third to write down the communication, and to direct the answer. The signals were made by moving boards, in a way somewhat analogous to the method presently to be described; and short sentences could be thus transmitted from Paris to Lisle in a few minutes.

The advantage of this telegraphic system was so soon felt, that Great Britain was not slow in adopting it; and from that time to the present telegraphs have been, at intervals, used in this country. Sometimes the signals were made by shutters moving in a frame; at others, by arms projecting from a vertical post; at others, by flags; at others (being for night), by lanthorns. Still more recently, the wonderful application of electricity to telegraphs has occurred: but this is too vast a subject for us to touch upon here.

If telegraphs were still employed only for the purposes first contemplated, viz. rapid communication of political and military intelligence, we should not probably have included a notice of them in this work; but there is now a system setting on foot which appeals so directly to the subject of civilization, as to come consistently within the scope of our object. This is, the establishment of telegraphs at various parts of the coast of Great Britain, and others from the coast to London, for the purpose of communicating instant intelligence of the arrival of vessels at any port; of vessels seen

Pentland Firth, Peterhead, Flamborough Head, Spurn, Yarmouth, Orfordness, North Foreland, Deal, Reculver, Sheppy, the Needles, and three places in the Isle of Wight. There is also a chain of stations to connect London with Deal; the first of which is now erecting on the top of a shot-tower at the foot of London Bridge; the second at Forest Hill; the third at Knockholt; and others at Wrotham Hill, Blue-bell Hill, and three or four elevated spots between there and Deal. These stations, by an agreement with the Trinity House, are in communication, not only with each other, but also with the floating lights at the Nore, the Goodwin Sands, &c. Most of the stations here

mentioned are now in course of preparation; but there is a short line, from the Spurn-light to Hull, which has been in practical operation for some time.

Thus much of the topographical arrangements. We may now proceed to the mechanism of the signals, the primary part of which, perhaps, is the "Telegraphic Dictionary." This is a printed octavo volume, of about 150 pages, prepared by Mr. Watson, a copy of which is kept at each station. It contains several thousand words, names, phrases, and directions, comprising such as are likely to be most useful to maritime and commercial men. Names of vessels, names of places, certain nautical

terms, &c., have been selected with great care, as may best suit the object in view. They are all ranged alphabetically, and each one has a number attached to it, which number becomes the symbol employed in signalling. For instance: in the dictionary (which we have been permitted to glance at), under the head of " Steam-boat," we find the following five phrases or remarks :"Steam-boat alongside." "Steam-boat is in sight."

"Steam-boat is going alongside." "Steam-boat cannot get alongside." "There is no steam-boat near." Each of which has a number attached to it. Suppose, now, that the London owner of a steamboat, which is out in the British Channel, wishes to know whether it has arrived within sight of Deal, and has forwarded, by signals, an inquiry to that effect; and let us further suppose that the number attached to the dictionary phrase, "There is no steam-boat near," be 1352; the signal-man at Deal exhibits symbols representative of the number 1352. The man at the next station, looking out with a telescope, sees the signal, and then proceeds to give a similar signal with his own telegraph. The number 1352 thus travels from station to station; and when it arrives at the London terminus of the chain, the dictionary is referred to, and it is then found that the number 1352 means, "There is no steamboat in sight,”—a specimen of plain English, which, if conveyed to the London shipowner, would at once give him the intelligence required. We have merely assumed this number 1352; the real numbers in the book need not, of course, be given here.

It will thus be seen that the telegraphic operation consists, in principle, of the transference from place to place of symbols representing numbers. The first substitution, viz. that of numbers for words or phrases, we have described, and may now briefly speak of the mode in which these numbers are represented. It might be supposed that if large numeral figures were cut out in wood or pasteboard, and held up at a considerable height, a telescopic observer at a distance might see them correctly; and such a plan was in former times partially adopted. In Mr. Watson's plan, however, the numbers are represented by the position which two or more boards, poles, or arms, are made to assume, with reference one to another; the general principles of which (though not the minute details) may perhaps be understood from the following description.

On proceeding to the telegraph on Forest Hill we perceive a small house or two, for the accommodation of the superintendant; and immediately in front is a large and lofty assemblage of poles, wire-ropes, &c. The main part consists of two vertical masts, about twenty feet apart, and fifty feet high. Two cross-trees or poles are fixed, one

near the top of each mast; and two pairs of arms are hinged to the lower part of each mast, one pair above another. There are thus eight arms, which, when not in use, are invisible at a small distance, because they fall into grooves in the masts; but when in use, each arm is capable of projecting out sideways, in one of three different directions, viz., inclining upwards, inclining downwards, and horizontal. Every arm is managed by means of a wire rope, which passes into the house, and is there moved by a sort of windlass.

Now let us for an instant confine our attention to one pair of arms, attached to the same mast at equal heights, the one branching out to the left and the other to the right. Calling one the north arm-when this inclines upwards, it signifies 1; when horizontal, 2; when it inclines downwards, 3. The south arm signifies 4, 5, and 6, when inclining upwards, horizontally, and downwards, respectively. Both arms inclining upwards signify 7; both horizontal, 8; and both inclining downwards, 9. It will thus be very apparent that any numeral from 1 to 9 may be symbolled by one or both of these arms, pointed obliquely or horizontally.

But if the number be higher than 9, the upper pair of arms in the same mast is brought into requisition. Here the positions are similar to those of the pair below; but each one is equivalent to a number ten times as great as the one below. If the lower north arm, inclining downwards, indicates 3, the upper north arm, inclining downwards, would indicate 30; and so of all the other positions. To indicate such a number as 79, therefore, the two upper arms would incline upwards for 70, and the two lower would incline downwards for 9.

Supposing, however, the number to reach hundreds or thousands, the other mast is employed, of which each pair of boards move precisely in the same way as the former. But the value of the indication is proportionably higher, the lower pair representing hundreds, and the upper pair thousands. These may all be compared in an easy way, by supposing the whole eight arms to project horizontally: then the lower pair on the first mast, as before observed, would represent 8; the upper pair, 80; the upper pair in the other mast, 800 ; and the lower, 8000: so that the whole would indicate the number 8888. Other instances may be inferred from this.

The mechanism by which all these are moved (invented, we believe, as well as the whole system to which it relates, by Mr. Watson) is extremely ingenious, but cannot be described in a popular way; nor indeed is it necessary so to do. Suffice it to say that, by a little preliminary arrangement, one winch-handle is made to raise all the arms at once, or any number requisite, and to the required angle. There are also provisions for making certain other signals, not included in the dictionary. It might, for instance, be necessary to communicate