The poem is written in the voice of a plain-speaking individual. The use of such contractions and other signs of a common, folksy accent stand in ironic contrast to the refined sensibilities of the astronomer. The irony works in kind of the same way as Reese Witherspoon's accent in Legally Blond, a movie about a California Valley Girl who goes to Harvard Law School. We should note that Whitman doesn't just adopt the plain-spoken tone in this poem – he slips in and out of it like a chameleon. But it functions slightly differently here, given the context.
- Title, line 1: The two-syllable word "learned" contracts to "learn'd," implying a plainspoken speaker without a sophisticated college education. It is ironic to use this tone to talk about a very sophisticated college professor.
- Lines 1-4: The repeated use of the word "when" at the beginning of the first four lines is an example of anaphora. It contributes to the impression that the speaker is telling a slightly rambling anecdote.
- Lines 3, 5 and 6: The speaker talks using parallel expressions that follow the formula, "this and that," "this and that." Examples include, "the charts and the diagrams," "tired and sick," and "rising and gliding out."
- Line 4: We think the repetition of "lecture" in these lines sounds especially folksy. The astronomer is clearly delivering a lecture in a lecture room: does he really need to tell us that this room is, um, a lecture-room?
- Line 6, 8: "Learn'd" is not the only contraction used in this poem. "Wander'd" and "look'd" are also contractions. "Look'd" is particularly baffling because the word is one syllable anyway.