WATSON'S TELEGRAPH
The view of the above edifice is taken from the Borough, and must be acknowledged by all who have seen it to be most correct. The plan was invented by a gentleman named Watson, and is carried into execution, we understand, by a body of enterprizing gentlemen calling themselves the "Shipping Telegraphic Association." As regards the topographical object of the telegraph, the intention is to establish it at various parts of the coast of Great Britain, and others from the roast to London, for the purpose of conveying instant intelligence of the arrival of vessels at any port; of vessels seen at a distance; of vessels in distress; of the kind of aid required and the place to which it must be sent; of orders given or required; of the number of passengers, or the kind and amount of cargo on board ; and numerous other matters arising out of maritime enterprize; of the manner in which lives and property may be saved by such a system.
    Coast Stations ore now or have already been established at Pentland Firth, Peterhead, Flamborough Head, Spurn, Yarmouth, Orfordness, North Foreland, Deal, Reculver, Sheppy, the Needles, and three places in the Isle of Wight. Thorn is also a chain of station, 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, Bluebell-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.
    With regard to the mechanism of the signals, it is necessary to state that the primary part is the "Telegraphic Dictionary;" a copy of which is kept at each station, and contains several thousand words, names, phrases, and directions, such as are likely to be most useful and required, and names of vessels, of places, and certain nautical terms, which 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 signaling.
     It will thus be seen that the telegraphic operation consists, in principle, of the transference from place to place of symbols representing numbers. In this plan 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.
    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 most, and two pairs of arms are hinged is the lower part of each mast, one pair above another. There are thus eight arms, which, when down in the grooves, are invisible at small distance. When in operation, one arm is capable of projecting sideways in one of three different directions, viz., 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.

from The Illustrated London News, 184