filled with "earnestness and sincerity," as the first narrator acknowledges.

Overall, the first narrator is more skeptical generally. He is uncertain that the request from a friend "from the East" was truthful and, as noted, appears skeptical about the veracity of Simon Wheeler's narrative.

By comparison, Simon Wheeler believes the story of Jim Smiley and the jumping frog of Calaveras County. His narration is also more colloquial and less refined. He uses words such as "feller" instead of fellow, "curiosest" instead of most curious and "reg'lar" instead of regular.

He also corrects himself, whereas the first narrator likely edited his writing several times before including it as the preface to Wheeler's text. For example, Simon Wheeler says,

"in the winter of '49 or maybe it was the spring of '50 I don't recollect exactly"

In fact, Simon Wheeler's portion of the narrative really sounds more verbal, as it is intended to sound. It authentically seems is as if Wheeler is speaking to the first narrator. Conversely, the first narrator appears to have written his text after giving careful consideration to the points he wants to make and his use of diction.

Mark Twain's "The Celebrated Jumping Frog of Calaveras County" is written as a frame story, with its initial narrator asking Simon Wheeler for information on one Leonidas W. Smiley, only to be told the story of Jim Smiley instead (after whose jumping frog the story takes its name). There is a striking contrast between these two narrators (in fact, I think much of the story's effect is built on that contrast).

The initial narrator is erudite and very precise in his use of language. Note, however, that he tends to use advanced vocabulary quite frequently (far more than what one would expect to find in modern literature, which tends to aim for linguistic clarity in this respect). He certainly has greater technical command of the English language than Simon Wheeler and is more disciplined in expressing it.

Simon Wheeler, on the other hand, is prone to rambling. Furthermore, note that his section is written in the vernacular. Mark Twain is trying to convey here real patterns of speech (whereas the initial narrator's use of language reflects a more formal mode of written English). That being said, I think that Simon Wheeler is probably the more natural storyteller of the two with how he creates a much stronger sense of narrative with a clearer plot progression, centered around memorable and clearly established characters.

Part of the humor of Mark Twain's story is the juxtaposition of the two narrators: one of the outer (frame) story and one of the story-in-a-story. The outer frame's narrator, known only as "I," is polite, formal, well-educated, from the East, and perhaps slightly irritable, or at least irritated. In contrast, Simon Wheeler is rather inconsiderate, relaxed, possibly poorly educated, from the West, and good-natured.

The first narrator makes a polite and very formal inquiry after a friend of a friend, telling Simon Wheeler that if he could supply any information, he "would feel under many obligations to him." He displays his formality and education by using fancy ways of conveying simple information, such as saying "a cherished companion of his boyhood" rather than simply "an old friend." The narrator's education and the fact that he has a friend from the East suggest that he, too, is originally from that more civilized part of the country. The narrator speaks of being bored to death and exasperated, showing that he is somewhat irritable or that he is irritated by the fact that he has been the butt of a joke by his friend. He seems to take his leave in the middle of Simon Wheeler's sentence. To be fair, the narrator is probably feigning his irritation; nevertheless, it stands in contrast to Wheeler's disposition. 

Simon Wheeler is quite different. Although he is certainly friendly, he lacks proper manners in that he infringes on the narrator's personal space, backing him into a corner and blockading him there and speaking non-stop. While the first narrator is stilted in his language, Simon Wheeler is unrefined and informal, using idioms, contractions, and colloquialisms freely. For example, he says, "He ketched a frog one day, and took him home, and said he cal'lated to educate him." Wheeler is obviously a fixture of Angel's Camp, a good example of a man of the West. But he's good-natured throughout the story, demonstrating great compassion and respect for the "heroes," both animal and human, in his tale. 

Twain portrays the two narrators as very different in personality, style, and education, which adds additional humor to his story.

The key to noticing the difference between the two narrators in the story is to look at the language and diction used.  For instance, the first narrator writes with a polished and formal diction, noting, "I called on good-natured, garrulous old Simon Wheeler, and inquired after your friend, Leonidas W. Smiley, as you requested me to do, and I hereunto append the result."  With words like "garrulous" and "hereunto," a reader rightly notes that even though the narrator is telling a story, he is still using an educated diction.  Compare that to Simon Wheeler, who starts his story in this way: "here was a feller here once by the name of Jim Smiley..."  His sentences and syntax meander along, and the reader gets the sense that he rarely takes a breath, or as the first narrator notes, "He never smiled, he never frowned, he never changed his voice from the gentle-flowing key to which he tuned the initial sentence."  The reader will also notices more colloquialisms such as "solitry" instead of "solitary" or "Thish-yer" instead of "This here."  All give indications that Simon Wheeler is not refined like the first narrator, and he likely grew up in the West or frontier, not the East like the first narrator.  

In his essay, "Mark Twain's 'Jumping Frog': Towards an American Heroic Ideal," Lawrence R. Smith contends that Mark Twain's story is satiric as a deadpan trickster named Simon Wheeler makes fun of the pompous narrator who presumes to call Wheeler "garrulous" at the onset of the story.  As the narrator makes inquiries about "a cherished companion of his boyhood named Leonidas W. Smiley," it becomes apparent that Simon Wheeler, with his Western dialect and less pedantic turn of phrase, satirizes the hypocrisy of the narrator who seeks the preacher:

Parson Walker's wife laid very sick once, for a good while, and it seemed as if they warn's going to save her; but one morning he come in, and Smiley asked how she was, and he said she was considerable better thank the Lord for his inftnit mercy and coming on so smart that, with the blessing of Providence, she'd get well yet; and Smiley, before he thought, says, "Well, I'll risk two- and-a-half that she don't, any way."

Thus, argues Smith, Twain sets up a contrast, not between the sophisticated and the vernacular voice, but rather between the false and the true.  Here, then, lies the irony.  For, it is the "monotonous narrative" of Wheeler which is effectively superior to the Eastern narrator who is made a fool of by Wheeler's trick within a trick within another trick. Ironically, then, the unsuspecting narrator departs tricked by the more clever Wheeler, saying only

But, by your leave, I did not think that a continuation of the history of the enterprising vagabond Jim Smiley would be likely to afford me much information concerning the Rev. Leonidas W. Smiley, and so I started away.

It is Twain, then, as narrator who becomes the butt of the joke.  Speaking in stilted English, this narrator represents the snobbery of the Eastern part of the United States in the 19th century, an area with which Twain was well acquainted as he lived in Conneticut.