Answer:
The signal fire.
Step-by-step explanation:
In Lord of the Flies by William Golding, the signal fire measures the boy's connection to civilization since it is on the mountains and then is lit on the beach so that ships and planes can see the stranded boys on the island. We can see that at the beginning, the boys try to keep the fire burning in the hopes of being rescued, but as the story develops and the group becomes more uncivilized, the fire does not burn with the same strength or does not burn at all, signaling that the boys have lost connection with their civilized part.