[Graybeard58]

I don’t know if it’s true, but I heard it was tapping at half hour intervals.

`````````````````````````````````````````````

Once upon a midnight dreary, while I pondered, weak and weary,
Over many a quaint and curious volume of forgotten lore—
While I nodded, nearly napping, suddenly there came a tapping,
As of some one gently rapping, rapping at my chamber door.
“’Tis some visitor,” I muttered, “tapping at my chamber door—
Only this and nothing more.”

[nickcarraway]

Nevermore

But maybe this incident does bear a passing resemblance to Poe's The Narrative of Arthur Gordon Pym of Nantucket.