"That lever, Guy; not too smart with it," exclaimed Leslie, indicating a small steel rod on the after bulkhead of the engine-room.
Acting upon instructions, Guy slowly depressed the lever. As he did so, he became aware of the fact that the whole fabric was rising. The sleigh was no longer supported by the runners, but by four flanged wheels; each pair coupled in a fore and aft direction by a broad spiked chain.
Throwing the clutch into the lowest gear, Leslie restarted the motors. At a speed of two miles an hour the huge vehicle moved towards the icy barrier. The motion was decidedly uncanny. It reminded Leslie of the erratic waddle of a tortoise. The lack of speed in spite of the fact that the motors were purring at a high rate of revolution, seemed to irritate him. He felt inclined to let the engine "all out."
Presently the sleigh began to tilt, the fore part rearing as the wheels encountered the stiff slope. Ranworth had chosen the easiest path, yet it necessitated a fifteen feet climb over a wall of ice, inclined at an angle of thirty degrees to the perpendicular.
Above the purr of the motors could be heard the crunching of the ice under the grip of the spiked wheels. Once or twice the vehicle faltered, then, recovering itself, slowly made its way up the steep incline.
Small projections of ice it simply pounded to a powder. Narrow fissures it bridged without any apparent effort, and although the crew had to hang on to the nearest support to prevent themselves sliding against the after-bulkhead, the lumbering "house on wheels" advanced with the ease of a fly walking on a ceiling.
Again Ranworth signalled for the motors to be switched off. The sleigh was now on the summit of the drift ice. In front of it lay the sea, the surface of which was quite twenty feet below the level on which the sleigh was perched.
"A tough job, Leslie," remarked Ranworth. "Think she'll do it?"
"She will right enough, sir," replied Leslie, confidently.
"Of course," added Ranworth, with a grim laugh. "But the question is, will she smash herself up in the attempt? There's no checking her, remember, once she gets over the brink."