My thoughts, however, became gradually less and less coherent, and I was just sliding over the verge of slumber, when a faint sound in the distance caught my ear.  I listened intently:  certainly there was a far-off, indistinct sound, different from the dull, continuous sweep of the wind.  I rose on the bench, fully awake, yet not excited, for my first thought was that other travellers might be lost or belated.  By this time the sound was quite distinct, and, to my great surprise, appeared to proceed from a drum, rapidly beaten.  I looked at my watch:  it was half-past ten.  Who could be out on the lonely prairie with a drum, at that time of night?  There must have been some military festival, some political caucus, some celebration of the Sons of Malta, or jubilation of the Society of the Thousand and One, and a few of the scattered members were enlivening their dark ride homewards.  While I was busy with these conjectures, the sound advanced nearer and nearer,—­and, what was very singular, without the least pause or variation,—­one steady, regular roll, ringing deep and clear through the night.

The shanty stood at a point where the stream, leaving its general southwestern course, bent at a sharp angle to the southeast, and faced very nearly in the latter direction.  As the sound of the drum came from the east, it seemed the more probable that it was caused by some person on the road which crossed the creek a quarter of a mile below.  Yet, on approaching nearer, it made directly for the shanty, moving, evidently, much more rapidly than a person could walk.  It then flashed upon my mind that this was the noise I was to hear, this the company I was to expect!  Louder and louder, deep, strong, and reverberating, rolling as if for a battle-charge, it came on:  it was now but a hundred yards distant,—­now but fifty,—­ten,—­just outside the rough clapboard-wall,—­but, while I had half risen to open the door, it passed directly through the wall and sounded at my very ears, inside the shanty!

The logs burned brightly on the hearth:  every object in the room could be seen more or less distinctly:  nothing was out of its place, nothing disturbed, yet the rafters almost shook under the roll of an invisible drum, beaten by invisible hands!  The sleepers tossed restlessly, and a deep groan, as if in semi-dream, came from the man.  Utterly confounded as I was, my sensations were not those of terror.  Each moment I doubted my senses, and each moment the terrific sound convinced me anew.  I do not know how long I sat thus in sheer, stupid amazement.  It may have been one minute, or fifteen, before the drum, passing over my head, through the boards again, commenced a slow march around the shanty.  When it had finished the first, and was about commencing the second round, I shook off my stupor, and determined to probe the mystery.  Opening the door, I advanced in an opposite direction to meet it.  Again the sound passed close beside my head, but I could see nothing, touch nothing.  Again it entered the shanty, and I followed.  I stirred up the fire, casting a strong illumination into the darkest corners; I thrust my hand into the very heart of the sound, I struck through it in all directions with a stick,—­still I saw nothing, touched nothing.