For all this the watch must have been very lax, as Gefhardt soon contrived to open communication with him again, and letters were passed through the window (to which the prisoner had made a false and movable frame) and forwarded to Trenck's rich friends. His appeal was always answered promptly and amply. More valuable than money were two files, also procured from Gefhardt, and by their means the new chains were speedily cut through, though, as before, without any apparent break. Having freed his limbs, he began to saw through the floor of his cell, which was of wood. Underneath, instead of hard rock, there was sand, which Trenck scooped out with his hands. This earth was passed through the window to Gefhardt, who removed it when he was on guard, and gave his friend pistols, a bayonet, and knives to assist him when he had finally made his escape. All seemed going smoothly. The foundations of the prison were only four feet deep, and Trenck's tunnel had reached a considerable distance when everything was again spoiled. A letter written by Trenck to Vienna fell into the hands of the governor, owing to some stupidity on the part of Gefhardt's wife, who had been intrusted to deliver it. The letter does not seem to have contained any special disclosure of his plan of escape, as the governor, who was still Duke Ferdinand of Brunswick, could find nothing wrong in Trenck's cell except the false window-frame. The cut chains, though examined, somehow escaped detection, from which we gather either that the officials were very careless, or the carpenter very stupid. Perhaps both may have been the case, for as the Seven Years' War (against Austria) was at this time raging, sentinels and officers were frequently changed, and prison discipline insensibly relaxed. Had this not been so, Trenck could never have been able to labor unseen, but as it was, he was merely deprived of his bed, as a punishment for tampering with the window. As soon as he had recovered from his fright and an illness which followed, he returned to his digging. It was necessary for him to bore under the subterranean gallery of the principal rampart, which was a distance of thirty-seven feet, and to get outside the foundation of the rampart. Beyond that was a door leading to the second rampart. Trenck was forced to work almost naked, for fear of raising the suspicions of the officials by his dirty clothes, but in spite of all his precautions and the wilful blindness of his guards, who as usual were on his side, all was at length discovered. His hole was filled up, and a year's work lost.