I have been one acquainted with the night.
I have walked out in rain—and back in rain.
I have outwalked the furthest city light.
I have looked down the saddest city lane.
I have passed by the watchman on his beat
And dropped my eyes, unwilling to explain.
I have stood still and stopped the sound of feet
When far away an interrupted cry
Came over houses from another street
But not to call me back or say good-bye;
And further still at an unearthly height
One luminary clock against the sky
Proclaimed the time was neither wrong nor right.
I have been one acquainted with the night.
“Unearthly” can often be used to mean “haunting” or “ominous” and the word conveys the dark tone that is present in this poem. 
 This line also leads into the next and follows the double entendre of the clock representing a literal tower clock or the moon. In the case of the moon, it would be literally at an “unearthly hight” because it isn’t on the earth.
Acquainted with the Night