Taken at face value the title simply refers to the lighting of the signal fire on the mountain top. It could also refer to the fact that the signal fire got out of control and set fire to a pocket of trees on the mountain side. However as symbolism is often used in Lord of the Flies the title could refer to beacon fires which were lit during war time as a warning that the enemy was approaching. This might be a veiled allusion to the fact that things were already beginning to go wrong on the island and the first cracks in their society had begun to appear.
In "Lord of the Flies," the fire on the mountain symbolizes the boys' hopes of being rescued and their connection to civilization. It also represents their ability to maintain order and coherence. As the story progresses and the fire becomes uncontrollable, it mirrors the boys' descent into savagery and loss of civilization.
it symbolizes hope of rescue
Piggy
Piggy was the last boy to reach the top of the mountain.
All of the boys climb the mountain and build a huge fire.
The mountain is mentioned in Lord of the Flies at various points throughout the novel. It is primarily associated with the signal fire that the boys try to maintain in order to signal passing ships for rescue. The mountain also becomes a symbolic focal point for the boys' struggle to maintain order and civilization on the island.
The boys in Lord of the Flies are from England, to quote Jack, in chapter 2: Fire on the Mountain... "After all, we're not savages. We're English; and the English are best at everything."
In "Lord of the Flies," Ralph discusses the importance of building a fire on page 38 (depending on the edition). He describes the fire as a potential means of rescue, highlighting its significance in maintaining hope and attracting passing ships.
Ralph said that a ship could see the smoke from up there and rescue them.
Ralph thinks that the beast on top of the mountain top is preventing them from the fire
In "Lord of the Flies," it is Simon who is tending the fire when the boys' fear of the beast emerges. As the boys mistake a dead paratrooper for the beast and flee, Simon remains at the scene and discovers the truth about the figure on the mountain.
The side of the island with the little bit of smoke in "Lord of the Flies" is the south side of the mountain. This is where the boys start a signal fire in an attempt to attract passing ships for rescue.
Chapter 2: Fire on the Mountain ended with the realisation by the boys that the littlun with the mulberry coloured birthmark on his face was no where to be seen. They realsied that he had probably burned to death when the fire had spread to the pocket of jungle on the slopes of the mountain.
When Ralph said, in chapter 8: Gift for the Darkness, and I quote "We've no fire. That thing sits up there-- we'll have to stay here." Piggy replied, "We got no fire on the mountain. But what's wrong with a fire down here?"