Final answer:
Personification in the text refers to an inanimate concept, Sylvia's 'great design', behaving like a human by keeping her awake. This literary device emphasizes the character's emotional turmoil and sleeplessness.
Step-by-step explanation:
The personification of sleeplessness is effectively illustrated in the provided text through several literary examples, which bring inanimate elements to life with human characteristics. One vivid instance of this can be found in the passage where the personified night is filled with actions and intents typically associated with living beings. Here, the example that stands out is:
"The young sportsman and his old hostess were sound asleep, but Sylvia's great design kept her broad awake and watching."
In this sentence, Sylvia's 'great design', an intangible concept, takes on human-like qualities, almost as if it were a companion keeping her awake with intent and purpose. Personification like this serves to deepen the reader's connection to the character's emotional state, underscoring their restlessness and distress during the sleepless night.