Stirling saw the reason for this: The copper of the can had no abrasive edge. He lowered the can, drew out his revolver, and started nicking the metal. Each blow sounded like a hammer stroke in his straining ears, and he feared to dent the bottom of the can so freely that it could not be straightened. He pocketed the revolver and felt the edge. It was rough, at any rate.
The improvised saw now cut into the overhead plank as he pressed the bolt upward with straining arms. The belt slipped at times, but he waited and tried anew. The power which was in the tail shaft of the engines was sufficient for a thousand saws.
Dust and splinters dropped down upon his tense face, but he held on grimly with one determination mastering his thoughts: The girl was in danger. She was barricaded in her stateroom, and the dock rat was probably sitting by the great table in the main cabin—with a vast reservoir of gin and whisky from which to draw.
Stirling felt the edge of the can bite through the plank in one place. He lowered it and examined the opening. The belt had stretched under the strain and had permitted a cut of seven or eight inches in length.
Crossing the belt, Stirling started a second cut at a right angle to the first, and worked on with his arms aching and growing numb from the strained position. The oil in the can had served for lubrication to the bolt, but when this oil dried, the bolt squeaked, and the can became hot.
He lowered it from the cut in the deck plank and the smell of hot oil in the shaft bearings gave him an idea. There was enough grease and oil packed with waste there to keep the bearings cool. He lifted a cover and dug out a handful of dripping packing, which he squeezed into the can. The bolt was now lubricated.
Though working in almost total darkness, he made rapid progress, and still no sound came from above. The dock rat probably was sleeping across the table; the girl had not moved in her cabin.
The first faint light which streamed through the crack he made steeled Stirling to renewed efforts. He enlarged the opening and stood erect.
The view was a limited one of an ornate ceiling stamped here and there with fresco and border designs. In the centre of this ceiling gleamed the frosty light from an electric dome. Three lamps burned, despite the fact that a soft glow was filling the splendid cabin. This glow came from the breaking dawn which made rosy the deck light and cabin companion.
Stirling removed his eye from the crack and felt the grooves he had cut in the planking. They were almost sufficient for his purpose. He trimmed a corner with his improvised saw, ran the saw through a deep cut till it severed the plank's edge, then pressed firmly upward. The trapdoor he had cut was held by only a few splinters.