Tom Swift and His Giant Cannon, Tom Swift and His Photo Telephone, Tom Swift and His Aerial Warship

Tom Swift Omnibus #6 contains a trio of stories: In the sixteenth of Victor Appleton's original Tom Swift novels, Tom and his father go in search of treasure along the Panama canal, and Tom develops a new type of artillery. In the seventeenth of Victor Appleton's original Tom Swift novels, Tom develops a precursor to twenty-first-century communication methods, and must use his invention to track down a group of unscrupulous financial manipulators. In the eighteenth of Victor Appleton's original Tom Swift novels, Tom goes up against foreign spies during the build-up to World War I.