Backwards and forwards he turned the condenser, and with a second knob altered the wavelength of his reception, first tuning in ships in the Channel signalling to their controlling station at Niton, in the Isle of Wight, or the North Foreland; then Leafield, in Oxfordshire, could be heard transmitting to Cairo, while Madrid was calling Ongar, and upon the highest wavelength the powerful Marconi station at Carnarvon was sending out a continuous stream of messages across the Atlantic.
Suddenly, as he reduced his wavelength below six hundred metres, he heard a man’s deep voice call:
“Hulloa, 3.V.N. Hulloa! This is 3.A.Z. answering. What I said was the truth. You will understand. Tell me that you do. It is important and very urgent. 3.A.Z. changing over.”
Who 3.A.Z. was, or who 3.V.N., Roddy did not at the moment know without looking up the call-letters in his list of experimental stations. The voice was, however, very strong, and evidently high power was being used.
He listened, and presently he heard a voice much fainter and evidently at a considerable distance, reply:
“Hulloa, 3.A.Z. This is 3.V.N. answering. No, I could not get you quite clearly then. Remember, I am at Nice. Kindly now repeat your message on a thousand metres. 3.V.N. over.”
Quickly Roddy increased his wavelength to a thousand metres, which he swiftly tested with his wave-metre, a box-like apparatus with buzzer and little electric bulb. Suddenly through the ether came the words even more clearly than before:
“Hulloa, 3.V.N. at Nice! Hulloa! This is 3.A.Z. repeating. I will repeat slowly. Please listen! 3.A.Z. repeating a message. Andrew Barclay leaves London to-morrow for Marseilles, where he will meet Mohamed Ben Azuz at the Hôtel Louvre et Paix. Will you go to Marseilles? Please reply. 3.A.Z. over.”
Roddy held his breath. Who could possibly be warning somebody in the south of France of his friend Barclay’s departure from Victoria to interview the Moorish Minister of the Interior regarding the concession?
Again he listened, and yet again came the far-off voice, faint, though yet distinct: