What figure of speech is used in these lines from William Shakespeare’s Romeo and Juliet?
But all so soon as the all-cheering sun
Should in the furthest east begin to draw
The shady curtains from Aurora's bed,
Away from the light steals home my heavy son,
And private in his chamber pens himself,
Shuts up his windows, locks far daylight out
And makes himself an artificial night:
Black and portentous must this humour prove,
Unless good counsel may the cause remove