Their three native sledges were open box-frames, ten feet by two in size and eighteen inches high, resting on wooden runners a foot high. Tough, pliant lashings of walrus hide bound together with the utmost tightness the frame and the runners. This method of construction, in which not a bit of iron enters, avoids rigidity and thus gives a flexibility and life to the sledge which enables it to withstand shocks and endure hard usage, which would soon break a solid frame into pieces. A cargo-cover of light canvas not only closely fits the bottom and sides of the box-frame but overlaps the top. When the cargo-cover is neatly hauled taut and is properly lashed to the sides of the sledge the load, if it has been snugly packed, is secure from accidents. Its compact mass is equally safe from thievish dogs, from the penetrating drift of the fierce blizzards, and from dangers of loss through jolts or capsizings. Of a single piece for each dog, the harness used by the natives is of seal-skin; the half-breeds often make it of light canvas, not only as better suited to the work but especially for its quality of non-eatableness which is a vital factor during days of dog-famine on long journeys. The harness is collar-shaped with three long bands; the collar slips over the dog's head and one band extends to the rear over the animal's back. The other bands pass downward between the dog's legs and, triced up on each side, are fastened permanently to the back-band, where there is also attached a drag-thong or pulling-trace about two feet long. In harnessing, the three loops described are slipped respectively over the head and legs of the dog. The animals are secured in pairs to the long draught-rope of the sledge by the Alaskan pioneers, who much prefer this method to the old plan of the natives whereby the dogs were strung out in single file. With the dogs in couples the draught-line is shorter, so that the better-controlled animals will haul a larger load. In the first day's journey they crossed a mountain range two thousand feet high, and in making the descent of the precipitous northern slope Jarvis records a sledging expedient almost unique in sledge travel. The four Eskimo drivers detached the dogs from the sledge, and winding around the runners small chains so as to sink in the deep snow and impede their progress, prepared to coast down the mountain. Two men secured themselves firmly on each sledge, and when once started the descent was so steep that the sledges attained a fearful speed, which brought them almost breathless to the bottom of the range in ten minutes.