The book begins: Some time in February, when the snow and sleet have shut out from the wearied mind even the memory of spring, the man of the woods generally receives his first inspiration. He may catch it from some companion's chance remark, a glance at the map, a vague recollection of a dim-past conversation, or it may flash on him from the mere pronouncement of a name. The first faint thrill of discovery leaves him cool, but gradually, with the increasing enthusiasm of cognition, the idea gains body, until finally it has grown to plan fit for discussion.