In his application of this method, not casually, playfully, and with satiric intent, as Voltaire had applied it, but seriously and taking it as the mainspring of his story, Poe added an ingenious improvement of his own devising.  Upon the preternaturally acute observer who was to control the machinery of the tale, the American poet bestowed a companion of only an average alertness and keenness; and to this commonplace companion the romancer confided the telling of the story.  By this seemingly simple device Poe doubled the effectiveness of his work, because this unobservant and unimaginative narrator of the unraveling of a tangled skein by an observant and imaginative analyst naturally recorded his own admiration and astonishment as the wonder was wrought before his eyes, so that the admiration and astonishment were transmitted directly and suggestively, to the readers of the narrative.

In the ‘Gold-Bug’ the wonder-worker is Legrand, and in both the ’Murders in the Rue Morgue’ and the ‘Purloined Letter’ he is M. Dupin; and in all three tales the telling of the story is entrusted to an anonymous narrator, serving not only as a sort of Greek chorus to hint to the spectators the emotions they ought to feel, but also as the describer of the personality and peculiarities of Legrand and Dupin, who are thus individualized, humanized, and related to the real world.  If they had not been accepted by the narrator as actual beings of flesh and blood, they might otherwise retain the thinness and the dryness of disembodied intelligences working in a vacuum.

This device of the transmitting narrator is indisputably valuable; and, properly enough, it reappears in the one series of detective tales which may be thought by some to rival Poe’s.  The alluring record of the investigations of Mr. Sherlock Holmes is the work of a certain Dr. Watson, a human being but little more clearly characterized than the anonymous narrators who have preserved for us the memory of Legrand and Dupin.  But Poe here again exhibited a more artistic reserve than any of his imitators, in so far as he refrained from the undue laudation of the strange intellectual feats which are the central interest of these three tales.  In the ‘Gold-Bug’ he even heightens his suspense by allowing the narrator to suggest that Legrand might be of unsound mind; and in the ‘Murders in the Rue Morgue’ the narrator, altho lost in astonishment at the acuteness of Dupin, never permits his admiration to become fulsome; he holds himself in, as tho fearing that overpraise might provoke a denial.  Moreover, Poe refrained from all exhibitions of Dupin’s skill merely for its own sake—­exhibitions only dazzling the spectators and not furthering his immediate purpose.