“I should have compelled them to remain in the cabin,” he groaned to himself. “Yes, that was my duty, in such a storm as that! I wish they were back--I’d give all I possess to bring them back!” And he continued his unsatisfactory walk back and forth, until even kind hearted Captain Danvier grew tired of seeing the movements. “You must calm yourself, my dear professor,” he said, in French. “It is very sad, my heart goes out to you. I know what it is. And why not? My own brother was washed from the deck in a storm and never seen afterward. And I had to be captain just the same and bring my vessel to the end of her trip. It was awful! Yes, I know how to feel for you,” and he clapped a friendly hand on Professor Strong’s shoulder. The air was murky and hot, so much so that even Sam and Darry noticed it. They saw the cloud of smoke at a great distance, looking at it through a marine glass the captain loaned them. “The cloud is hanging over the northern end of the island of Martinique,” said the professor. “There must be some sort of a forest fire raging there.” Soon somebody on deck reported that his eyes were filled with dust. Half a dozen passengers and sailors were affected, and the dust became so thick that it covered everything and made it look gray. This was a most unusual occurrence and the professor was appealed to for an explanation. “This appears to be pumice,” he said, after an examination with a microscope. “And if it is, it is most likely of volcanic origin. Pumice is very light--so light that it will float on the water--which this is doing. It is formed, so scientists say, by the gas coming out of lava while the latter is in a melted state.” “But where does it come from?” questioned Darry, who could not help but be interested. “Is there any active volcano around here?” “This pumice is so light that a fair wind will carry it for many miles, Dartworth.” “The wind is blowing up from the south-east,” put in Sam. “Do you suppose it came from Martinique? That big black cloud looks suspicious to me.” “Perhaps Mont Pelee has become active again!” cried Darry. “It certainly looks so.” And he pointed to the cloud, which looked blacker than ever. “That is not impossible,” said the professor. “You remember I told you that that volcano had been active many times in the past. But I doubt if the eruption will amount to anything. The volcano is considered to be about burnt out.” “Yes, it is no longer dangerous,” put in Captain Danvier, speaking in French. “I myself was to the top with an excursion party but two months ago. There was a beautiful lake there and no sign of fire. An outbreak there would amount to but little.” And then he told how he had often discussed the volcano with his friends at St. Pierre and Fort de France and how all had agreed that the volcano’s activity was of the past,--that is, so far as its capabilities for doing much damage was concerned.