To Ralph, keeping the fire ablaze is the only way for the boys to ever be rescued. In addition to serving as a signal to any passing planes or ships, it also cooks the meat brought home by Jack and his hunters. For Jack, this purpose is the main importance of the fire. Partly because Jack has no respect for Ralph after losing the "election" as chief, Jack sees little need for the signal fire to keep blazing. In his mind, it takes time away from the hunt. As for the fire going out in Chapter 2, the boys built the fire too big and it grew out of control, threatening to destroy a good part of the island. In their frenzy, they piled too much wood on the fire which eventually collapsed upon itself. Ralph saw that the fire did not produce enough smoke, signifying that it probably needed to be watched more carefully with small, green brush and wood applied in order to produce better signal smoke.