The signal fire was a symbol of civilization, and the boys' attempts and willingness to return to society and real life. You can use this as a gague throughout the book to tell how close or how far away the boys are from society, and when they've given up all hope of being rescued..
At the beginning of the book, the boys set up a fire at the highest point on the island. This fire is to be a signal to flag down any ships that might be passing by and then could rescue the lost children. This fire burns strongly for a while, but as the boys pass to being more and more savage, they let the fir…
