At Sixty Mile they restocked provisions, added a few pounds of letters to their load, and held steadily on. From Forty Mile they had had unbroken trail, and they could look forward only to unbroken trail clear to Dyea. Daylight stood it magnificently, but the killing pace was beginning to tell on Kama. His pride kept his mouth shut, but the result of the chilling of his lungs in the cold snap could not be concealed. Microscopically small had been the edges of the lung-tissue touched by the frost, but they now began to slough off, giving rise to a dry, hacking cough. Any unusually severe exertion precipitated spells of coughing, during which he was almost like a man in a fit. The blood congested in his eyes till they bulged, while the tears ran down his cheeks. A whiff of the smoke from frying bacon would start him off for a half-hour's paroxysm, and he kept carefully to windward when Daylight was cooking.
They plodded days upon days and without end over the soft, unpacked snow. It was hard, monotonous work, with none of the joy and blood-stir that went with flying over hard surface. Now one man to the fore in the snowshoes, and now the other, it was a case of stubborn, unmitigated plod. A yard of powdery snow had to be pressed down, and the wide-webbed shoe, under a man's weight, sank a full dozen inches into the soft surface. Snowshoe work, under such conditions, called for the use of muscles other than those used in ordinary walking. From step to step the rising foot could not come up and forward on a slant. It had to be raised perpendicularly. When the snowshoe was pressed into the snow, its nose was confronted by a vertical wall of snow twelve inches high. If the foot, in rising, slanted forward the slightest bit, the nose of the shoe penetrated the obstructing wall and tipped downward till the heel of the shoe struck the man's leg behind. Thus up, straight up, twelve inches, each foot must be raised every time and all the time, ere the forward swing from the knee could begin.