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 …showed first 75 words of 397 total…

…showed last 75 words of 397 total…Out of this act of savagery comes a twist, because the fire turns from being a horrible, destructive thing to a signal fire, and it attracts a ship, and they are saved. The signal fire burned bright when the kids had hope, and went dark when all hope was lost. In the end, all the boys' attempts at making a signal fire for rescue fail, and their saving comes, ironically, from an act of savagery.