For nearly two hundred feet she kept a course almost parallel with the end of the glacier; then, turning abruptly, she headed towards the shelving ice which the lads had selected as the best place for taking the water.
Suddenly the ice creaked and cracked ominously. There was no going back. The momentum of the sleigh was too great to allow its onward course to be checked.
The next instant, instead of descending an easy gradient, the Bird of Freedom was tilting sideways at an alarming angle. She had gained a large floe which had just become detached from the main portion of the glacier, and that floe was bodily capsizing.
The decapod wheels gripped the ice, until the angle of the smooth face of the floe became too acute. With a horrible, sickening movement, the sleigh began to slide sideways. It reminded Guy of a motor car skidding on a slippery road.
Leslie had the presence of mind to cut off the electric current. More he could not do. He braced himself for the impending catastrophe, for the Bird of Freedom was in imminent danger either of being thrown bodily against the hard face of an ice cliff or of being crushed by the overturning of the enormous floe.
He was dimly aware that the angle formed by the floor and one side of the cabin was filled with a crowd of struggling men, thrown thither like sheep by the extreme list of the sleigh; then, with a terrific crash, the Bird of Freedom toppled completely over.
A cascade of icy water poured in through a jagged gap in the roof, which was now undermost. Then, like a cork, the Bird of Freedom righted herself, and tossed violently on the surface of the agitated sea, with two feet of water surging along the cabin floor and over the desperately struggling men.
Leslie, who had gripped one of the guard rails surrounding the motors, had performed a remarkable acrobatic feat on the impromptu horizontal bar, and as the Bird of Freedom resumed her normal position he found himself lying across the engines, slightly bruised, but otherwise unhurt.
A quick glance through the nearest scuttle told him that for the present the water-borne sleigh was out of danger, unless she had sprung a leak below the water line.
"We're afloat all right!" he shouted.