What are the main differences between the 1902 and 1908 versions of "To Build a Fire" by Jack London?
There are some important differences between the 1902 version and the one published in 1908, which is the version most people know. In the earlier version, the man has a name, Tom Vincent, and we know a little more about him; he is young and proud of his strength. There is no dog in the earlier story. Some of the details are different -- in the earlier version, Tom finds a hunter's lodge, but it is uninhabited. London's description of how liquid water could exist in such cold is more detailed in the earlier version. In the 1902 version, there is no "old timer" who offers advice. Most significantly, the man survives in the earlier story, while in the 1908 version he freezes to death.
I think the most important difference between the two is tone, however. In the earlier version, the point of the story is to drive home the truth of the Northern maxim, "Never travel alone!" Tom learns a valuable lesson about the cold, and emerges from this experience a wiser man.
In the later story, however, the tone is much darker, and more philosophical. In a sense, the 1908 version shows that the man's lack of respect for the tremendous cold dooms him to death. But more than that, the story also suggests that nature is an all-powerful, and completely indifferent force. London seems to be saying that it doesn't matter to nature whether the man lives or dies; nature is not there to teach any lessons -- it just is. Ignore it at your peril.