What is the symbolic meaning of the the rumbling peals like thunder that came from the old men's bowling balls?Washington Irving's "Rip van Winkle"

Washington Irving's "Rip van Winkle" shares some of the
common narrative elements, or motifs, of folk tales such as the mysterious beings, and
a potion that induces the enchanted slumber.

When Rip van
Winkle wanders off on "his long ramble of the kind on a fine autumnal day," he finds
himself on one of the highest parts of the Kaatskill (now Catskill) Mountains.  The
sound of "rolling peals like distant thunder"  and the
noise of balls which roll and echo like this thunder represent the sound
of gunfire and the cannon balls being fired during the American
Revolution.

It is typical of Rip van Winkle that he would
not want to recognize a battle for what it is since he, then, might have to become
involved.  The men around him are perceived as small, perhaps, because they are, then,
not worthy of van Winkle's serious attention.  And, in his effort to escape any serious
thought, van Winkle eagerly takes draft after draft from the flagon of liquor.  And,
when he awakens, he blames the "wicked flagon." 

What is so
humorous about the "scrupulous accuracy" of Irving's repetition of Diedrich
Knickerbocker's tale is the whimsical irony put into it.  For, Rip van Winkle chooses to
ignore the approaching Revolution in his mind which represents the Romantic penchant of
Irving, who indicates in van Winkle's return his nostalgia for the pre-revolutionary
days of the past.