The case of a wireless installation used for a motor-car, however, presents much more difficulty of detection. We might know perfectly well that it was being used, and yet be unable to locate it on account of its mobility. It is practically certain that it would never be used twice from the same spot; indeed, it might operate along a line running a couple of hundred miles north and south, and still convey its messages to the enemy vessels. In such a case as this, we can only rely upon vigilance and good luck to turn the trick in our favour. In my view, the Admiralty took an extremely unwise step when, at the beginning of the war, they closed all the private wireless stations in England. There are a great many of these stations--far more than the general public realises--and the majority of them were being worked by men whose loyalty and discretion stood absolutely above suspicion. These installations--free from the heavy load of business thrown upon the Government coast stations--are quite capable of doing excellent work in constantly "listening" for illicit stations which might be in the hands of German spies for the purpose of giving information respecting our naval movements. The value of these small stations as a means of detecting hostile messages has been entirely under-estimated by the Admiralty, who seem to consider the risk of Englishmen being either traitors or fools more than outweighs the possibility of detecting secret wireless in the hands of our enemies. I have dwelt upon this matter at some length, because I am absolutely convinced of the very serious danger to which we are exposed from the use of wireless installations, small, but capable of working over any distance up to, say, one hundred miles--and even less would be amply sufficient--by German spies in Great Britain at the present moment.