Of secret installations there are, no doubt, to-day, many in various parts of the country. Several stations have, indeed, been discovered. The reason aliens were not allowed to possess a telephone was regarded as curious by some people. But it was because telephone-wires, when properly insulated and arranged, make quite a good "aerial." Further, in any barn or long attic, aerial wires can be strung across, and give excellent results. The spy does not need spidery wires upon masts high above his house-top, or in his garden. If his instruments are sufficiently delicate, and are connected with the underground gas-pipe, or even to an ordinary wire-mattress, he will be able to receive messages from any of the high-power stations within a radius of, say, five hundred miles, while from a wire strung inside a disused factory-chimney, and thereby hidden, a wireless message can be despatched a couple of hundred miles. Therefore the peril of all this will at once be realised, for any spy who knows sufficient to fit up a wireless station inside his own house, and is acquainted with the latest developments of the science, need not use lamp-signalling at night, or pigeons, or any other antiquated modes of communication. Indeed, he can flash at night a code-message direct to Norddeich or any other place on the German coast, and receive back his answer in a few moments, no one being able to detect, until after long search and inquiry, whence the mysterious buzz has emanated. It ought to be said, however, that it is problematical how long such a fixed station, established say in Yorkshire, could be worked without detection, because its messages must--sooner or later--be picked up by some of our own Post Office or naval operators. The messages would be in cipher, of course, but the important thing would be to know that such a plant was being used. An expert wireless-operator, with a newly-invented instrument called a "direction-finder," can make a very good guess at the distance of the point of origin of any message he receives, and once the proper authorities were on the track of a secret wireless station, the work of hunting it down would be only a matter of time and trouble. Such a case was reported a few weeks ago from the Pacific coast, where a wireless station established in the centre of a remote district was giving the Germans valuable help. It was tracked down and located, and it is said that a similar station was found in the centre of Rome, and others in Paris and Antwerp. We might be equally successful here, but, in the meantime, it is more than likely that a good deal of damage might have been done.