"That's right," agreed his brother. "We've looked for some opening, or natural shaft, but haven't been able to find it. Sometimes we shoot off a charge and everything goes well, the smoke disappears in a few minutes. Again it will all blow out this way and we lose half a day waiting for the air to clear. There's a hidden shaft, or natural chimney, I'm sure, but we can't find it."
"Thot blast didn't make much racket," commented Tim Sullivan. "I doubt thot much rock come down. An' thot's not sayin' anythin' ag'in yer powder, lad," he went on to Tom.
"Oh, that's all right," Tom Swift replied, with a laugh. "My explosive doesn't work by sound. It has lots of power, but it doesn't produce much concussion."
"We've often made more noise with our blasts," confirmed Job Titus, "but I can't say much for our results."
They were all anxious, Tom included, to hurry into the tunnel to see how much rock had been loosened by the blast, but it was not safe to venture in until the fumes had been allowed to disperse. In about an hour, however, Tim Sullivan, venturing part way in, sniffed the air and called:
"It's all right, byes! Air's clear. Now come on!"
They all hurried eagerly into the shaft, Mr. Damon stumbling along at Tom's side, as anxious as the lad himself. Before they reached the face of the cliff against which the bore had been driven, and which was as a solid wall of rock to further progress, they began to tread on fragments of stone.
"Well, it blew some as far back as here," said Walter Titus. "That's a good sign."
"I hope so," Tom remarked.
There were still some fumes noticeable in the tunnel, and Mr. Damon complained of a slight feeling of illness, while Koku, who kept at Tom's side, murmured that it made his eyes smart. But the sensations soon passed.