Hobby-horse
Laurence Stern uses sexual imagery to enhance his concept of the "hobby-horse," or the one topic each person wants to talk on and on about. His examples - Uncle Toby and war, for example - are incorporated into the plot, but Sterne's tactile words makes the concept more general than it would otherwise be. The choice of imagery prevents this generalization from losing its relation to the reader.
Tristram's Birth
Sterne provides mostly details of Tristram's surroundings, so the story of Tristram's grotesque entrance to the world helps center the novel. The strange mutilation of Tristram's nose is written with a dry sense of humor, but the visual description makes his characterization and thus narration real.
The Clock
Tristram's parents ritualize their clock, and the full transition of Tristram's narration to the clock itself helps the reader understand how the mechanics of this distraction works. The imagery of this clock creates a character trait of Tristram's parents as a unit through the tactile information of winding.
Window Sash
Another of Tristram's tactile events involves the dropping of a window sash when he was only an infant. Sterne's imagery demonstrates the breadth of the novel's narration and the extent to which the novel engorges the heretofore short life of the protagonist; the incident forever changes Tristram's body, which Sterne thoroughly describes.
