Here lies, as it seems to me, the possible material for a great national disaster. Such a fleet of transports cannot be rushed suddenly across. Its preparation and port of departure are known. A single submarine amid such a fleet would be like a fox in a poultry yard destroying victim after victim. The possibilities are appalling, for it might be not one submarine, but a squadron. The terrified transports would scatter over the ocean to find safety in any port. Their convoy could do little to help them. It would be a debacle--an inversion of the Spanish Armada. If the crossing were direct from the eastern ports to Antwerp, the danger would become greater.[6] It is less if it should be from Portsmouth to Havre. But this is a transit of seven hours, and the railways from Havre to the Belgian frontier would be insufficient for such a force. No doubt the Straits of Dover would be strongly patrolled by our own torpedo craft, and the crossing would, so far as possible, be made at night, when submarines have their minimum of efficiency; but, none the less, it seems to me that the risk would be a very real and pressing one. What possible patrol could make sure of heading off a squadron of submarines? I should imagine it to be as difficult as to bar the Straits to a school of whales. [6] This, of course, would presuppose that Holland was involved in the war.--A. C. D. But supposing such a wholesale tragedy were avoided, and that in spite of the predominance of submarines the army got safely to France or to Belgium, how are we to ensure the safe passage of the long stream of ships which, for many months, would be employed in carrying the needful supplies? We could not do it. The army might very well find itself utterly isolated, with its line of communications completely broken down, at a time when the demand upon the resources of all Continental countries was so great that there was no surplus for our use. Such a state of affairs seems to me to be a perfectly possible one, and to form, with the chance of a disaster to the transports, the greatest danger to which we should be exposed in a German war. But these dangers and the food question, which has already been treated, can all be absolutely provided against in a manner which is not only effective, but which will be of equal value in peace and in war. The Channel Tunnel is essential to Great Britain's safety.