This poem talks about an astronomer lecturing the narratoráæs class. The narrator áç[becomes] tired and sickáè implying he is bored by the class and dazes off to his fantasy. While he thinks the class is boring, the audiences give the astronomer áçmuch applause in the lecture-roomáè.
Whitman uses repetition, starting the first four lines with áçwhenáè to emphasize how boring the class is. This also shows an orderly and tensed feeling and is elaborated through his choice of words. He uses words such as proofs, figures, columns, charts, and diagrams to support the systematic astronomer lecture. The systematic words reflect a strict sense of science, contrasting nature not having an orderly manner. The narrator finds it extremely dull to view nature in a scientific way.
Whitman shows how the class is uninteresting compared to when the narrator dazes off in his wonderland, and áç[looks] up in perfect silence at the stars.áè
The last three lines show how nature should not be viewed in a systematic way, but rather with a Romantic attitude. áçMystical moist night-airáè and áçperfect silence at the starsáè show a comfortable feeling and inner peace towards the stars in the sky. It also slows relaxation compared to the tensed lecture.
The attitudes toward science and nature are very contrasting in this poem. Although it seems like the narrator loves astronomy, he feels bored in this lecture class. The narrator simply loves the beauty of nature. However, when nature is approached with a scientific perspective, it alters his view from interesting to tedious.