21 OCTOBER 1882, Page 8

THE SCIENTIFIC REPORT ON THE CHANNEL TUNNEL.

THE 13lue-book on the Channel Tunnel ought to dispose of the scheme until the Millennium. When wars have become matter of history, and nations have no longer any motive for attacking their neighbours, those who wish to enjoy a twenty miles' journey in an atmosphere resembling that of the Metro- politan Railway will, perhaps, have the opportunity of doing so. There will no longer be any War Office to whisper dis- satisfaction, or any Commander-in-Chief to protest on military grounds. But until this happy time arrives, the promoter's of a Channel Tunnel must submit to have their project con- demned on its merits. It cannot hope to endure the

criticism of Sir Garnet Wolseley, or the very weighty Memorandum by the Duke of Cambridge. In the latter, especially, there are some points which are either new, or stated with a force which makes them as good as new. For example, the Duke especially urges upon the attention of Ministers " the peculiar geographical position of Calais." It is a mistake to treat the Tunnel as dangerous only in the event of a rupture with France. "Calais lies in so isolated a position, on the extreme north of the French coast-line, and the boundary between France and Belgium falls away so rapidly to the south from near Calais, that Antwerp and Brussels are both much nearer to Calais than Paris is. Any Power, therefore, which, when at war with France, had taken possession of Belgium would find it possible to seize Calais, and might find it convenient to punish an alliance of ours with France by a sudden seizure of Dover." As regards the power of the Military Authorities to destroy the Tunnel at a moment's notice, the Duke asks the Government to consider "whether the time when there was a prospect of war, and when our relations with a foreign Government had reached a strained condition, would be that precise moment which an English Cabinet would choose for ordering even the temporary stoppage of the Tunnel, an act which would be taken by the inhabitants of both countries as a sure indication of coming war." Yet it would be in this interval that the greatest danger of the Tunnel being suddenly seized would arise. "Unless, therefore," the Duke goes on, "it is quite certain that no foreign Government that had written angry despatches on the subject of alleged grievances will ever sud- denly and seriously make up its mind, that, war being in- evitable, it is better to anticipate diplomatic forms, and by means of treachery or surprise obtain possession of so all- important a prize as the fortress on which the whole security of England would then depend, it is idle to trust to protec- tion which only guarantees our safety when ample warning is given." In support of this view, the Duke refers to an un- published paper, giving a list of wars commenced without previous declaration, which, as he maintains, "shows con- clusively that wars have commenced much more frequently during the course of diplomatic correspondence than after all diplomatic relations have been broken off ; that again and again fortresses have been seized unprepared and without resistance, because their defenders were not aware that they had any reason to expect attack." Let us now look at the Report of the Military Committee. It is to be noted, in the first place, that it absolutely condemns the two existing projects of a Channel Tunnel. In Sir Edward Watkin's scheme, the mouth of the Tunnel is within range of effective fire from the sea, and it is not within the command of the advanced works or any work of a fortress, so that be- fore the scheme could fulfil the conditions laid down by the Committee, "an entirely new and very powerful fortress would have to be constructed, at great expense." The rival project is equally open to objection as having its mouth within range of effective fire from the sea, and it is not commanded by the advanced works of a fortress, It is in the heart of the main defences of Dover Castle and in the midst of the town, so that any fire that would protect it would "inflict great injuries on the town and its inhabitant's." Still, either of these schemes might be altered so as to meet these objections. It must next be asked, therefore, what the general conclusion of the Committee amounts to ? They say, in effect, that if all the precautions they recommend are taken and maintained in their full efficiency, it ought to be impossible for an enemy to make any use of the Tunnel in any imaginable contingency. But they admit, as every reasonable man must admit, that "in dealing with physical agencies, an amount of uncertainty exists which can never be wholly eliminated, and that it is equally impossible to eliminate human fallibility." Even more than this might be said. When every imaginable contingency had been guarded against, there would remain the unimaginable; • and in war, things are occasionally done which had occurred to no one as possible, until they have actually been achieved. It is not necessary, however, to go beyond the warning of the Committee to find ample arguments against the construction of a Tunnel. Let it be granted that the precautions determined on are, in all respects, sufficient, what answer is there to the remark that "a long period of peace and uninterrupted tranquillity might en- gender carelessness in maintaining in good working condition the arrangements applied to the partial or complete destruction of the Tunnel, and might lead to fortifications being left so

inefficiently armed or insufficiently manned as not to be secure against surprise ?" The arrangements proposed to secure the partial or complete destruction of the Tunnel are in the highest degree complicated. At the mouth of the Tunnel, a portcullis is to be placed, by the act of closing which one or more lengths of rail will be removed, and a trap-bridge raised. To guard against the mouth. of the Tunnel. being surprised before the portcullis can be closed, means must be provided for stop- ping ventilation by closing the air-shafts, for discharging irrespirable gases into the interior, and for rapidly de- livering shingle through channels specially provided for the purpose. All these obstructions could easily be removed, and the Tunnel put again into working order in a short time. To provide for the temporary demolition of the Tunnel, mine gal- leries would have to be carried either alongside, above, or below the Tunnel; in which charges sufficient to destroy for a considerable distance the walls, roof, or floor might be per- lnanently kept. As a preliminary to the firing of these mines, a large, unconfined charge of explosives might be kept ready at hand, on a truck, to be started at any moment down the line, with a time fuse attached to it. As an alternative to this expedient, explosive charges may be lowered into the air shafts, and for this purpose electric cables should be kept ready laid to the upper openings of the shafts. The temporary flooding of the Tunnel is to be provided for by sluice-valves, the means of opening and closing which are to be .placed within the fortress. The destruction of the Tunnel would be effected by the simultaneous discharge of mines constructed between the bed of the sea and the roof of the Tunnel, "so that their explosion should make a breach into both, and thus admit the sea." All these mines should be controlled, not only from the central fort, and from any out- works the Commander might think proper to place in com- munication with them, but from one or more distant places. In this way, the power of permanently destroying the Tunnel might be retained, even after the protecting fortress had fallen.

Yet when all these multiplied precautions had been taken, what would be their real value? On the principle of the strength of the chain being judged by its weakest link, just nothing at all. Colonel Webber, who was for many years in charge of all the telegraph wires of the Post Office through- out the South of England, says:—" It would be a wiser act for a General to leave the success of a battle dependent on a telegraph wire, than for the nation to trust to a conductor between London and Dover for the destruction of a tunnel at a supreme moment." Not only can no wire that is not constantly tested be depended on for acting at a given moment, but after years of good maintenance a wire might be tested at noon, and in the afternoon it might be found, on the need for using it suddenly arising, that an ordinary electrical fault arising from one of a hundred causes had occurred in the interval, and had rendered the labour of years useless. This might happen when all the arrangements were in perfect order, but then we have Sir Garnet Wolseley's testimony, founded on his knowledge of our military stations all over the world, that in time of peace our arrangements never are in perfect order. Ms experience supplies no guarantee "that all your electrical apparatus will be in perfect order, or that your slu:ce-gates will be in perfect order, or that contrivances which have been designed before-hand for rendering this Tunnel useless will have any effect, when you want them." These are only a part of the objections to any project for tunnelling the Channel, but it seems scarcely possible that it can be necessary to bring forward any more.