Impatiently the young lieutenant-commander of the Calder awaited a further signal announcing the result of the investigations. When it came it was highly satisfactory.
"Thanks be for small mercies!" ejaculated Crosthwaite fervently. "Signal M'Kie and tell him to take due precautions in case a ground swell sets in from the east'ard."
The cable was one of three that in pre-war time connected the little Norfolk fishing-village of Bacton with the German island of Borkum. Two more ran from Borkum to Lowestoft, the whole system being partly British and partly German controlled.
Immediately upon the declaration of war the telegraph cables had been severed, both in the neighbourhood of the British coast and in the vicinity of the German island fortress. To all intents and purposes it seemed as if the cables were nothing more than useless cores of copper encased in gutta-percha, rotting in the ooze on the bed of the North Sea.
Yet in spite of the most stringent precautions on the part of the British Government to prevent a leakage of news, the disconcerting fact remained that, thanks to an efficient and extensive espionage system, information, especially relating to the movements of the Grand Fleet, did reach Germany.
Various illicit means of communication were suspected by the authorities, and drastic, though none the less highly necessary, regulations were put into force that had the effect of reducing the leakage to a minimum.
Simultaneously a campaign was opened against the use of wireless installations. Undoubtedly wireless played its part in the spies' work, but its efficacy was doubtful. It could be "tapped"; its source of agency could be located. However beneficial in times of peace, it was a two-edged weapon in war.
For a long time the British Government failed to unravel the secret, until it was suggested that the submarine cables had been repaired. And this was precisely what had been done. The Huns had promptly repaired their end of one of the Bacton-Borkum lines, while a German trawler, disguised as a Dutch fishing-boat, had grappled the severed end just beyond the British three-mile limit.
To the recovered end was fixed a light india-rubber-covered cable. This would be sufficiently strong to outlast the duration of the war, the scarcity of gutta-percha and the enormous weight of the finished cable being prohibitive. It was paid out from the trawler with considerable rapidity, the end being buoyed and dropped overboard some miles from the spot where the original cable used to land. In the inky blackness of a dark winter's night a boat manned by German agents disguised as British fishermen succeeded in recovering the light cable and taking it ashore. Here it was a brief and simple matter to carry the line to a cottage on the edge of the low cliff, burying the land portion in the sand.
For nearly eighteen months the secret wireless station had been in active operation. News culled from all the naval bases by trustworthy German agents was surreptitiously communicated to the operators in the little unsuspected Norfolk cottage and thence telegraphed to Borkum.