That day preparations were made for setting off a great charge of the powerful explosive. The work was hurried as fast as was consistent with safety, but even then progress was rather slow. Precautions had to be taken, and the guards about the tunnel were doubled. For it was feared that some word of what was about to be done would reach the rival firm, who might try desperate means to prevent the completion of the work.
There was plenty of the explosive on hand, for Mr. Swift had sent Tom a large shipment. All this while no word had come from Mr. Nestor, and Tom was beginning to think that his prospective father-in-law was very angry with him. Nor had Mary written.
Professor Bumper came and went as he pleased, but his quest was regarded as hopeless now. Tom and his friends had little time for the bald-headed scientist, for they were too much interested in the success of the big blast.
"Well, we'll set her off to-morrow," Tom said one night, after a hard day's work. "The rocky wall is honeycombed with explosive. If all goes well we ought to bring down enough rock to keep the gangs busy night and day."
Everything was in readiness. What would the morrow bring—success or failure?
Chapter XXIV
The Hidden City
Gathered beyond the mouth of the tunnel, far enough away so that the wind of the great blast would not bowl them over like ten pins, stood Tom Swift and his friends. In his hand Tom held the battery box, the setting of the switch in which would complete the electrical circuit and set off the hundreds of pounds of explosive buried deep in the hard rock.
"Are all the men out?" asked the young inventor of Tim Sullivan, who had charge of this important matter. Tim was in sole charge as foreman now, having picked up enough of the Indian language to get along without an interpreter.