(1)The sky was like a waterdrop
 In shadow of a thorn,
 Clear, tranquil, beautiful,
 Dark, forlorn.
 (5)Lightning along its margin ran;
 A rumour of the sea
 Rose in profundity and sank
 Into infinity.
 Lofty and few the elms, the stars
 (10)In the vast boughs most bright;
 I stood a dreamer in a dream
 In the unstirring night.
 Why is "dark, forlorn" (line 4) separated on a line by itself?
 to emphasize the contrast between the characteristics of the waterdrop and the thorn
 to enhance the meter of the poem
 to create a stanza that has only four lines
 to help with the visual aspect of the poem
 to give a break in thought