The Frenchman supposes it the voice of a Spaniard, and
      ‘might have distinguished some words _had he been acquainted with
      the Spanish._’ The Dutchman maintains it to have been that of a
      Frenchman; but we find it stated that ‘_not understanding French
      this witness was examined through an interpreter._’ The
      Englishman thinks it the voice of a German, and ‘_does not
      understand German._’ The Spaniard ‘is sure’ that it was that of
      an Englishman, but ‘judges by the intonation’ altogether, ‘_as he
      has no knowledge of the English._’ The Italian believes it the
      voice of a Russian, but ‘_has never conversed with a native of
      Russia._’ A second Frenchman differs, moreover, with the first,
      and is positive that the voice was that of an Italian; but, _not
      being cognizant of that tongue_, is, like the Spaniard,
      ‘convinced by the intonation.’ Now, how strangely unusual must
      that voice have really been, about which such testimony as this
      _could_ have been elicited!—in whose _tones_, even, denizens of
      the five great divisions of Europe could recognise nothing
      familiar! You will say that it might have been the voice of an
      Asiatic—of an African. Neither Asiatics nor Africans abound in
      Paris; but, without denying the inference, I will now merely call
      your attention to three points. The voice is termed by one
      witness ‘harsh rather than shrill.’ It is represented by two
      others to have been ‘quick and _unequal._’ No words—no sounds
      resembling words—were by any witness mentioned as
      distinguishable. “I know not,” continued Dupin, “what impression I may have made,
      so far, upon your own understanding; but I do not hesitate to say
      that legitimate deductions even from this portion of the
      testimony—the portion respecting the gruff and shrill voices—are
      in themselves sufficient to engender a suspicion which should
      give direction to all farther progress in the investigation of
      the mystery. I said ‘legitimate deductions;’ but my meaning is
      not thus fully expressed. I designed to imply that the deductions
      are the _sole_ proper ones, and that the suspicion arises
      _inevitably_ from them as the single result. What the suspicion
      is, however, I will not say just yet. I merely wish you to bear
      in mind that, with myself, it was sufficiently forcible to give a
      definite form—a certain tendency—to my inquiries in the chamber. “Let us now transport ourselves, in fancy, to this chamber. What
      shall we first seek here? The means of egress employed by the
      murderers. It is not too much to say that neither of us believe
      in præternatural events. Madame and Mademoiselle L’Espanaye were
      not destroyed by spirits. The doers of the deed were material,
      and escaped materially. Then how? Fortunately, there is but one
      mode of reasoning upon the point, and that mode _must_ lead us to
      a definite decision. Let us examine, each by each, the possible
      means of egress. It is clear that the assassins were in the room
      where Mademoiselle L’Espanaye was found, or at least in the room
      adjoining, when the party ascended the stairs. It is then only
      from these two apartments that we have to seek issues. The police
      have laid bare the floors, the ceilings, and the masonry of the
      walls, in every direction. No _secret_ issues could have escaped
      their vigilance. But, not trusting to _their_ eyes, I examined
      with my own. There were, then, no secret issues. Both doors
      leading from the rooms into the passage were securely locked,
      with the keys inside. Let us turn to the chimneys. These,
      although of ordinary width for some eight or ten feet above the
      hearths, will not admit, throughout their extent, the body of a
      large cat. The impossibility of egress, by means already stated,
      being thus absolute, we are reduced to the windows. Through those
      of the front room no one could have escaped without notice from
      the crowd in the street. The murderers _must_ have passed, then,
      through those of the back room. Now, brought to this conclusion
      in so unequivocal a manner as we are, it is not our part, as
      reasoners, to reject it on account of apparent impossibilities. It is only left for us to prove that these apparent
      ‘impossibilities’ are, in reality, not such. “There are two windows in the chamber. One of them is
      unobstructed by furniture, and is wholly visible. The lower
      portion of the other is hidden from view by the head of the
      unwieldy bedstead which is thrust close up against it. The former
      was found securely fastened from within. It resisted the utmost
      force of those who endeavored to raise it. A large gimlet-hole
      had been pierced in its frame to the left, and a very stout nail
      was found fitted therein, nearly to the head. Upon examining the
      other window, a similar nail was seen similarly fitted in it; and
      a vigorous attempt to raise this sash, failed also. The police
      were now entirely satisfied that egress had not been in these
      directions. And, _therefore_, it was thought a matter of
      supererogation to withdraw the nails and open the windows. “My own examination was somewhat more particular, and was so for
      the reason I have just given—because here it was, I knew, that
      all apparent impossibilities _must_ be proved to be not such in
      reality. “I proceeded to think thus—_a posteriori_. The murderers did
      escape from one of these windows. This being so, they could not
      have refastened the sashes from the inside, as they were found
      fastened;—the consideration which put a stop, through its
      obviousness, to the scrutiny of the police in this quarter. Yet
      the sashes _were_ fastened. They _must_, then, have the power of
      fastening themselves. There was no escape from this conclusion. I
      stepped to the unobstructed casement, withdrew the nail with some
      difficulty and attempted to raise the sash. It resisted all my
      efforts, as I had anticipated. A concealed spring must, I now
      know, exist; and this corroboration of my idea convinced me that
      my premises at least, were correct, however mysterious still
      appeared the circumstances attending the nails. A careful search
      soon brought to light the hidden spring. I pressed it, and,
      satisfied with the discovery, forbore to upraise the sash. “I now replaced the nail and regarded it attentively. A person
      passing out through this window might have reclosed it, and the
      spring would have caught—but the nail could not have been
      replaced. The conclusion was plain, and again narrowed in the
      field of my investigations.