In Chapter 2 of Lord of The Flies, how does Piggy contribute to the survival of the boys?
Piggy's "specs" are used to start the signal fire. The boys' real knowledge of fire-making is decidedly minimal at best, as Jack tried to take the lead:
"You rub two sticks. You rub--"
He glanced at Ralph, who blurted out the last confession of incompetence.
"Has anyone got any matches?""You make a bow and spin the arrow," said Roger. (40)
Of course, the boys are at a loss for what to do. Roger has a good idea with using the bow and arrow method to create friction and heat to manufacture a spark to start the fire, but this method is extremely difficult, even for seasoned woodsmen. As Piggy enters the scene, Jack spies his glasses and quickly appropriates them for making the fire. Despite Piggy's lack of social skills or physical prowess, his unwilling contribution of his glasses to start fire makes a huge positive impact for the well-being of the tribe.
The most obvious point is that Piggy's glasses are used to build the fire which Ralph later admits has two purposes. Pg 179 - "This was the first time he had admitted the double function of the fire... " The two key functions of the fire are Rescue (smoke formed from the fire may be seen by a ship) and for safety (the light from the fire gives them reassurance) and many view the beast only at night because they mistake objects whilst it is dark. Sam and Eric mistake the dead parachutist for the beast but had they seen it in daylight, like Simon does then they may have realised that it is only a corpse.