What is a summary of chapter 20 of "Lyddie"?

In Chapter
20,continues to stay vigilant but indifferent to Mr. Marsden's lack of regard. She is simply
pleased that he chooses to ignore her. To keep her mind off her unprincipled supervisor, Lyddie
decides to treat herself to some books.

In honor of Ezekiel Freeman, a former
slave and her friend, she purchases the Narrative of the Life of Frederick
Douglass and the Bible; both volumes are a great comfort to her on lonely Sundays.
Lyddie also enjoys Charles Dickens' account of his travels to America. As the summer progresses,
more and more New England workers leave. Meanwhile, Irish workers take up new places at the
looms.

To keep up her courage, Lyddie copies out passages from the book of
Psalms and Frederick Douglass' narrative to paste on her looms. Meanwhile, she and Brigid begin
to coach several of the new workers. Lyddie marvels at Brigid's patience with the girls, while
Brigid admires Lyddie's scholarly spirit. In due time, however, Lyddie discovers that Brigid is
illiterate. Lyddie then begins on a mission to teach her friend how to read, beginning with an
introduction to the alphabet.

Soon, a letter arrives from Charlie, who
informs Lyddie that Rachel has begun school again and that her cough is nearly gone. He begs her
to consider Luke Stevens' suit. As the fall approaches, a letter arrives to inform Lyddie of her
mother's death. Lyddie finds that she can hardly mourn; she feels that her mother had been lost
to her long before death took her.

In the fall, the days get shorter, and the
whale oil lamps must burn longer. Lyddie continues her lessons with Brigid but is surprised when
Brigid fails to show up for one of their sessions at the end of a particular shift. Lyddie goes
in search of her friend and eventually finds Brigid alone in the weaving room with Mr. Marsden.
Seeing Mr. Marsden's hands clamped on Brigid's arms, Lyddie crams a bucket full of stagnant
water over Mr. Marsden's head.

This gives Lyddie time to drag the beleaguered
Brigid away from their overseer. Meanwhile, Mr. Marsden's efforts to get the bucket off his head
remind Lyddie of the bear trying to do the same thing in her family's cabin at the beginning of
the book. The scene is so funny that Lyddie can't help breaking into uncontrollable laughter as
she drags Brigid to safety.