In chapter 8, what myth begins the chapter and how is it developed in the chapter?
The myth in the beginning of the chapter belongs to Mr. Avery. He believed that it was "written on the Rosetta Stone that when children disobeyed their parents, smoked cigarettes and made war on each other, the seasons would change." It is clear from the beginning that the superstitions don't just belong to the children. The adults have theirs as well.
Many of the people in Maycomb share beliefs that if the natural order of things isn't balanced, the weather will pay them back for it. The first snow in years is a hint in that direction. In this chapter, the children build the mud-snow-man which one can see is both black and white. Social unrest is around the corner for this town, and the fire just adds to the tension. What is interesting is that after the fire is over, it is Jem who realizes that Boo came out that night to "take care of his children" when they needed a blanket/comfort.
All along the children have had their superstitions about Boo. Jem is now figuring out that Boo is just trying to be friendly. Scout is still clueless, which adds to the humor as Jem explains about Boo and the blanket. "My stomach turned to water and I nearly threw up." But the one rational person is Miss Maudie. She needed a larger garden and a smaller house. She has no superstitions and she sees the glass as "half full."