The Summary of Harry Potter Book 1, Chapter 17 is as follows:
Harry, Ron, and Hermione are in the library, trying to find a book on the history of Hogwarts. They are having no luck, until they stumble across a book called "Hogwarts, A History." Hermione is excited to find the book, and starts reading it immediately.
The book tells the history of Hogwarts from its founding by the four wizarding families, to the present day. Harry, Ron, and Hermione are surprised to learn that there have been many famous witches and wizards who have attended Hogwarts over the years.
After reading the book for a while, the three friends are caught by Madam Pince, the librarian. She is not happy to see them in the restricted section, and they are forced to leave the library.