Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Educated, Compassionate
The narrator's tone in this book pretty much reflects the kind of spirit Gaskell would like her readers to apply to the real world. Gaskell obviously places a high value on education and reading, since she begins every single chapter of this book with a reference to some book or author she's read.
Sometimes, these epigraphs don't even add anything to the actual chapter, as we see with the first epigraph, which just reads, "Wooed and married and a" (1.1.E). To that we say, respectfully, "??!??!WTF???!?, Gaskell?"
But often, they're right on the money and super-smart. At the beginning of a chapter that deals with Margaret's opinion clashing with Mrs. Thornton's, Gaskell supplies the epigraph "Thought fights with thought;/out springs a spark of truth/ From the collision of the sword and shield" (1.15.1). Oh, we get it! Gaskell is wittily comparing Margaret and Mrs. Thornton's animosity to an actual battlefield, and saying that truth comes from conflict.
Way to go, Gaskell. One other reason why Gaskell would want to show off her quoting skillz is because, as a woman writer in the nineteenth-century, she would have needed to prove to her male readers that she had done enough reading of her own to write about serious subjects like labor rights. The quote above, by the super-intellectual poet W.S. Landor, makes the point that fighting with words is just as truth-producing as fighting with swords. This quote, in effect, tells anyone who suspects Gaskell of being a feeble woman that language is just as violent (and effective) as an actual weapon.
On top of her constant literary allusions, Gaskell makes an effort to portray her characters as sympathetically as possible, even when they're being annoying. For example, Gaskell writes of Mr. Hale that he "was utterly listless, and incapable of deciding on anything" (1.21.36) after his wife's death. She wants us to have sympathy for the guy; he's heartbroken.