Barney had heard the sounds also, and both sat silently gazing at each other. What did it mean? Startling queries and theories flashed through the minds of each. Was some one coming to their rescue through the earth? Or was it all a delusion? The former theory was at once dispelled. If any friends knew of their presence there they would scarcely go to the trouble of rescuing them by means of digging through a thousand feet of earth. A few moments’ pulling at the mouth of the shaft would have brought them both out of their difficulty. As for the latter possibility it was at once dismissed. “Begorra, Misther Frank,” said Barney, in a mystified way, “phwativer do yez call that?” “Somebody is digging their way toward us,” said Frank. “Shure yez don’t suppose it is fairies?” whispered the superstitious Celt. “Nonsense!” Frank had hit upon what he believed to be the truth in his own mind. It had occurred to him that the greasers were conducting mining operations in these hills. Might it not be that in their shaft sinking they had followed a vein dangerously near the old shaft? In fact, it was not impossible that in a few hours they might not dig their way actually through into the old mine. The thought gave Frank a deep thrill of hope. “Barney,” he said, earnestly, “upon my soul, I believe that we are bound to make our escape.” “Shure, Misther Frank, phwat do yez mean?” cried Barney, in surprise. “Hush! let us wait and watch.” For some time the two prisoners listened to the sounds of the pickaxes, and the voices of the workmen could almost be distinguished. Suddenly, however, the sounds ceased. All was quiet beyond the wall of earth. What did it mean? Without doubt the miners had ceased work. Then Frank recollected the hour, and that without doubt they had retired for the purpose of gaining sleep. With an inspiration the young inventor sprang up. “Barney!” he cried. “Our time has come!” The Celt was astonished. “Shure, phwat do yez mean, Misther Frank?” “I mean that we must dig our way through and meet that passage. It will be deserted, and though it will lead us into the camp of the greasers, we will stand a chance to escape.” Barney caught the inspiration. “Bejabers, ye’re right!” he cried. “But how will we do it? Shure, we ’aven’t any pick nor shovel.” “Somewhere in this mine there must be some old ones!” cried Frank. “Let us search.” “It will likely be in the ould mine below, sor.” “All right.” “Shall we go down, sor?” “Yes.” Barney quickly adjusted the rope and slid down into the old shaft. Frank followed him. Then with the pocket lantern they began an exploration of the place, and with most gratifying results. In one corner they found part of an old spade and an iron bar. The bar could be used in lieu of a pickaxe. They quickly returned to the upper level. First making sure that they were not likely to be heard, work was begun. Frank wielded the bar and Barney the shovel.