"If there came a big slide here it would block the Canal," observed Mr. Alcando, speculatively.
"Yes, but what would cause a slide?" asked the captain.
"Dynamite could do it," was the low-voiced answer.
"Dynamite? Yes, but that is guarded against," the commander said. "We are taking no chances. Now, boys, you get a good view of Culebra," and he pointed ahead. Blake and Joe were soon busy with their cameras, making different sets of views.
"Hand me that other roll of film; will you, please?" asked Blake of the Spaniard, who was helping them. "Mine is used up."
As Mr. Alcando passed over the box he muttered, though possibly he was unaware of it:
"Yes, dynamite here, or at the dam, would do the work."
"What—what's that?" cried Blake, in surprise.