While most of the Devon boys would think that the purpose of skiing is to enjoy the exhilarating feeling of speed on a downhill run, Leper says,
"Skiing isn't supposed to be fast. Skis are for useful locomotion."
Leper skis to "go along and see what (he's) passing and enjoy (him)self." He thinks that people ruin skiing by having themselves carted up hills and then whizzing back down. Leper prefers to use skiing as a way of getting around in the snow, and at present, his purpose is to find a beaver dam to discover how beavers get along in the winter.
Leper marches to a different drummer than his peers. While the other boys are "keyed up" and "competing," totally swept up in the phenomenon of the war, he is almost oblivious to what is going on around him, existing instead in his own peaceful, placid world. When the formation of the railroad work detail for the war effort was announced that morning, Leper probably didn't even hear it, or if he did, he quickly put it out of his mind, so absorbed was he in ruminating about the beaver dam, and the natural world as it exists for him. When he sees Gene, he "mildly and curiously" asks him what he is doing, and when Gene tells him he is going to work on the railroad, Leper tells him to "have a nice day at it, anyway," and goes off to do his own thing.
Because Leper is so different from the other boys at Devon, Gene notes that "it was always a fight...to (avoid) making fun of him," but, in Gene's case at least, as he "had gotten to know (Leper) better this fight had been easier to win" (Chapter 7).