Why didn't the boys think about moving the fire before in chapter 8 on page 129?
Ralph and Piggy are extremely conflicted about what to do with the fire in chapter eight, "A Gift for the Darkness." Originally, Ralph had instructed the boys to build the fire on the mountain, the highest point on the island, where the smoke signals could be best viewed by passing ships or airplanes. Ralph's perfect plan for rescue, however, is challenged by the appearance of the 'beast' on the mountain; of course, the beast is really the dead parachuter, but the boys only perceive the hulking silhouette as a horrible beast. With the presence of the beast on the mountain, now they can no longer keep the signal fire lit. As Ralph and Piggy debate the possibilities, it is Piggy who first sees the solution:
"'No go, Piggy. We've got no fire. That thing sits up there--we'll have to stay here.'
Piggy lifted the conch as though to add power to his next words.
'We got no fire on the mountain. But what's wrong with a fire down here? A fire could be built on them rocks. On the sand, even. We'd make smoke just the same' (129).
Piggy's solution is born of desperation. The boys did not consider moving the fire earlier, because the taller vantage point of the mountain is the ideal location. They also had enough man-power to sustain the fire and keep watch over it. With Jack and the hunters' desertion, Ralph and Piggy must think practically. Piggy, one of the most rational-minded boys on the island, finds the simplest possible solution. This scene in the story is a powerful reminder that the characters in this story are just boys after all, and their ability to use logic and problem solving are extremely limited.