“When I Heard the Learn’d Astronomer” begins by repeating the title, something that often occurs in Whitman’s poetry and gives extra weight to the first phrase, to set up the idea that the speaker is listening to an educated scientist. This phrase also stands out because of its internal rhyme, or rhyme within the same line, of “heard” with “learn’d.” This is also a slant rhyme, or an inexact rhyme, since “learn’d” has an “n” sound unlike “heard,” but it nevertheless emphasizes a sense of repetition. The slant rhyme even gives the first line an impression of awkwardness, since it is difficult to pronounce and uses the same long vowel sound twice in a row.
The other element of the first line to notice is use of the contracted version of “learned.” Whitman frequently contracts words such as this, which would always be spelled out today, partly in an attempt to capture the way people actually spoke, instead of a high prose style. In this context, the contraction places some distance between the speaker of the poem, or the voice of the narrator, and the educated astronomer to whom he is listening. The poet may be suggesting here that the speaker uses a different, perhaps a more common or lower class, style of expression from the learned scientist.
Line 2 of the poem then presents the interesting image of “proofs” and “figures” of mathematical equations “ranged,” or arranged, in “columns.” Notice that the poem’s first four lines become increasingly longer, unlike these columns, which presumably go straight up and down within the same horizontal space. If a poetic line stretches beyond the margin, the standard method of printing that line is to continue it below, after an indentation. If a poetic line is continued in this way, therefore, it does not change the fact that the line should be considered to extend further and further to the right. Thus Whitman is likely to be contrasting the visual poetic expansion in the lines with the columned mathematical expansion of the astronomer’s proofs.
The third line, in which the speaker is shown materials related to astronomy and asked to manipulate mathematical equations, is full of mathematical diction, or word choice, such as “charts,” “diagrams,” “add,” “divide,” and “measure.” These words make up almost the entire line, and they are likely to overwhelm the reader, as they will increasingly overwhelm the speaker. That the speaker is asked to “add, divide, and measure” the “charts and diagrams” also emphasizes the negative side of the process, as though the lecture has nothing to do with the sky but merely manipulates its own figures.
(The entire section is 1139 words.)