The boys continued on their way for a few minutes, and then ran into another cloud of smoke. This was of a peculiar bluish-green cast, and seemed so sulphurous they were nearly choked by it.
"Listen!" burst out Andy. "I think I heard somebody calling."
He held up one hand for silence, and all listened attentively. In spite of the roaring of the flames, which were now devouring several of the buildings at the shell-loading plant, and the continual popping of some of the smaller shells, all heard a frantic cry for assistance.
"I think the cry came from over yonder," said Jack, in answer to the latter question. "Let's pull over there and see."
All were willing, and the four once more bent to their oars, sending the rowboat through the bluish-green smoke, which almost choked and blinded them.
"Hello there!" yelled Fred. "Where are you?"
"Help! Help!" came the cry from off to their left. "Help! Save me!"
The rowboat was turned in that direction, and a few seconds later the Rover boys caught sight through the smoke of a water-logged rowboat to which an elderly man, dressed in the garb of a workman, was clinging.
"Help me! Help me! I can't hang on much longer!" gasped the man, as soon as he saw the boys.
"Sure, we'll help you," declared Jack. "Go slow now," he cautioned his cousins. "We don't want to knock him off into the water."
With care the rowboat was brought around so that they came up alongside of the elderly man. He was glad enough to turn from his water-logged craft to the other boat. But he was well-nigh exhausted, and the Rovers had not a little trouble in getting him on board.
"Tell you what--I'm mighty glad you lads came along," panted the old man, when he was safe. "I couldn't have held out much longer. This is something terrible, ain't it? Say, would you mind hooking that boat fast and pulling it to shore? It belongs to me, and I ain't so wealthy that I can afford to lose it. Besides, it's got some of my things in it."
"We'll take it along unless it keeps us back too much," answered Jack. And then he bent down, got hold of the bowline of the craft, and tied it fast to their stern. Fortunately the other boat was a small one, so they had not much difficulty in towing it along.