“They were all terribly footsore. No spring or rebound was left in them. Their feet fell heavily on the trail, jarring their bodies and doubling the fatigue of a day's travel. There was nothing the matter with them except that they were dead tired. It was not the dead tiredness that comes through brief and excessive effort, from which recovery is a matter of hours; but it was the dead tiredness that comes through the slow and prolonged strength drainage of months of toil. There was no power of recuperation left, no reserve strength to call ....