Tom Swift And His Big Tunnel, Or, The Hidden City Of The Andes — Victor Appleton

The Titus Brothers Contractors company have won a government contract in Peru to blast a tunnel through a mountain and connect two isolated railroad lines. The deadline is approaching, and the contractors have hit a literal wall: excessively hard rock which defies conventional blasting techniques. The company is under pressure to finish, or else the contract will default to their rivals, Blakeson & Grinder. Mr. Job Titus has heard of Tom Swift and Tom's giant cannon, which is used in protecting the Panama Canal, and wants to hire Tom to develop a special blasting powder to help them finish the excavation.