At the termination of this sentence I started, and for a moment paused; for it appeared to me (although I at once concluded that my excited fancy had deceived me)—­it appeared to me that, from some very remote portion of the mansion there came, indistinctly, to my ears what might have been, in its exact similarity of character, the echo (but a stifled and dull one certainly) of the very cracking and ripping sound which Sir Launcelot had so particularly described.  It was, beyond doubt, the coincidence alone which had arrested my attention; for amid the rattling of the sashes of the casements, and, the ordinary commingled noises of the still-increasing storm, the sound, in itself, had nothing, surely, which should have interested or disturbed me.  I continued the story.

* * * * * * * *

Here again I paused abruptly, and now with a feeling of wild amazement—­for there could be no doubt whatever that, in this instance, I did actually hear (although from what direction it proceeded I found it impossible to say) a low and apparently distant, but harsh, protracted, and most unusual screaming or grating sound, the exact counterpart of what my fancy had already conjured up for the dragon’s unnatural shriek, as described by the romancer.  Oppressed, as I certainly was, upon the occurrence of this second and most extraordinary coincidence, by a thousand conflicting sensations, in which wonder and extreme terror were predominant, I still retained sufficient presence of mind to avoid exciting, by any observation, the sensitive nervousness of my companion.  I was by no means certain that he had noticed the sounds in question; although, assuredly, a strange alteration had, during the last few minutes, taken place in his demeanor.  From a position fronting my own he had gradually brought round his chair so as to sit with his face to the door of the chamber, and thus I could but partially perceive his features, although I saw that his lips trembled as if he were murmuring inaudibly.  His head had dropped upon his breast; yet I knew that he was not asleep, from the wide and rigid opening of the eye as I caught a glance of it in profile.  The motion of his body, too, was at variance with this idea; for he rocked from side to side with a gentle yet constant and uniform sway.  Having rapidly taken notice of all this I resumed the narrative of Sir Launcelot.

* * * * * * * *

No sooner had these syllables passed my lips than—­as if a shield of brass had indeed, at the moment, fallen heavily upon a floor of silver—­I became aware of a distinct, hollow, metallic, and clangorous, yet apparently muffled, reverberation.  Completely unnerved, I leaped to my feet; but the measured, rocking movement of Usher was undisturbed.  I rushed to the chair in which he sat.  His eyes were bent fixedly before him, and throughout his whole countenance there reigned a stony rigidity.  But as I placed my hand upon his shoulder there came a strong shudder over his whole person; a sickly smile quivered about his lips; and I saw that he spoke in a low, hurried, and gibbering manner, as if unconscious of my presence.  Bending closely over him, I at length drank in the hideous import of his words.