What are some quotes from the novel "The Lord of the Flies" that depict how Jack uses fear, ritual, and violence to gain and maintain control of the other boys?

In Chapter 8, Jack and his hunters kill a pig and decide to sever its head as a sacrifice to the beast. Leaving the head of a pig for the beast would be considered a hunting ritual that also serves as a way to promulgate fear. Jack tells the boys,

"This head is for the beast. It’s a gift" (Golding 197).

In Chapter 10, Jack tells his savages to improve the wall at Castle Rock in order to defend the gate. He mentions that the other boys might try to sneak in, then says,

"—and then, the beast might try to come in. You remember how he crawled—...He came—disguised. He may come again even though we gave him the head of our kill to eat. So watch; and be careful" (Golding 230).

This quote demonstrates how Jack uses the fear of the beast to coerce the boys into following his directives. Jack manipulates the boys the by using their fear of the beast to control them.
In a conversation between Roger and Robert, Jack's violence as means to control to his tribe is discussed. Roger tells Robert, "He’s going to beat Wilfred" (Golding 229). When Robert asks why, Roger says,

"I don’t know. He didn’t say. He got angry and made us tie Wilfred up. He’s been—he’s been tied for hours, waiting—" (Golding 229).

Jack's tyrannical leadership is portrayed in the way that he randomly punishes members of his tribe without explanation. Jack increases his power by using violence to intimate boys who disagree with his commands.