Tragedy
Bradley uses similes to describe the nature of Shakespearean tragedy, and the fact that tragedy seems to "descend from the clouds like lightning, or stealing from the darkness like a pestilence." This emphasizes the unpredictable nature of fate.
Macbeth's guilt
The horrible visions of Macbeth's crime and guilt "hold him spell-bound and possess him wholly, like a hypnotic trance which is at the same time the ecstasy of a poet," according to Bradley. This simile is used to describe how fixated and consumed Macbeth is by his guilt.
Russian bear simile
Macbeth uses a simile to confront the ghost of Banquo, saying:
"What man dare, I dare: Approach thou like the rugged Russian bear."
Here, he is challenging the ghost to approach him like a frightening creature, suggesting that Macbeth will not let this affect him.
Nautical metaphors
Bradley comments on Iago's use of "nautical phrases and metaphors," and how he does this more than Shakespeare's other characters. He explains that this is perhaps due the character's "roving military life."
Fleance simile
Bradley discusses the following simile from Macbeth: "A heavy summons lies like lead upon me." This quote is said by Fleance, who is oppressed and weighed-down with dark thoughts and visions.