What he had seen was this: A large barn-like building erected against the side of a hill surrounded by smaller huts and out in the open, removed at some distance from the other buildings, a large, retort-shaped blast furnace, from the mouth of which was pouring a column of copper-colored flame and a great efflorescence of sparks. It was this furnace doubtless that had caused the column of smoke they had seen during the day.
In the bright light cast by the flaming mouth of the retort he could see dark figures scurrying around, some of them with wheelbarrows which they pushed up an inclined plane leading to the side of the retort. From their barrows they constantly dumped something into the furnace. What it could be of course Frank had no means of knowing, but he guessed that it was some substance used in the manufacture of Chapinite. The whole scene reminded Frank of one of the foundries in the iron district, seen from a car window at night.
With the aid of the night-glasses he could make out details more plainly. The workmen were being urged to even greater activity by a tall man who was evidently in authority. From time to time this man raised a whip he held in his hand and brought its lash down viciously on the back of some unfortunate worker with a crack that was audible even at the distance the boys were.
“Oh Lawd, dat look like Hades for sho’!” groaned Quatty as his eyes almost popped out of his head at the weird scene. “Dem not men, Massa Frank, dems all debbils.”
“Pole her along a bit!” ordered Frank, not paying any attention to this outburst. He was bent on getting near enough to ascertain, if possible, if the unfortunate Lieutenant Chapin was one of the crew of laborers.
With frequent orders to stop from Frank which were obeyed by Quatty with alacrity and commands to proceed once more, which did not meet with the same eager response, the boat drew nearer and nearer to the blazing retort and the frenzied workers. As they were still in between high banks of saw-grass the boys had no fear of being seen unless of course some canoe from the island happened to come down the stream they were threading. As it was a narrow twisting, little runnel, however, with barely a foot of water under their keel, this did not seem likely.
All at once, however, they emerged without warning into a broad smooth-flowing channel worthy of the name of a river. The boys saw at once that this was indeed a main-traveled water-course and most probably the one used by the men on the island in getting to and from the coast.
“Get back where we were as quick as you can,” sharply ordered Frank as they glided out onto its broad current.
With a dexterous twist Quatty—quite as much alarmed as the boys at the prospect of discovery by the workers on the island—shot the boat back into the narrow grass-walled creek they had been traversing. It was well they had done so, for hardly had they gained the welcome shelter of the tall saw-grass when they heard the rapid “dip-dip” of paddles coming toward them down the main channel.
“Keep perfectly quiet,” ordered Frank, and scarcely breathing the boys listened with straining ears to catch the conversation the men in the approaching craft were carrying on.