> When I heard the learn'd astronomer,
> When the proofs, the figures, were ranged in columns before me,
> When I was shown the charts and diagrams, to add, divide, and measure them,
> When I sitting heard the astronomer where he lectured with much applause in the lecture-room,
> How soon unaccountable I became tired and sick,
> Till rising and gliding out I wander'd off by myself,
> In the mystical moist night-air, and from time to time,
> Look'd up in perfect silence at the stars.
In these lines, the speaker initially attends a lecture delivered by an astronomer, where he is presented with scientific knowledge, proofs, figures, and diagrams. However, rather than feeling enlightened or impressed, he suddenly becomes "tired and sick," indicating a growing dissatisfaction with the limitations of rational and scientific explanations.
Consequently, the speaker chooses to leave the lecture room and ventures outside into the "mystical moist night-air." This departure can be interpreted as a rejection of purely intellectual and abstract understanding in favour of direct, personal experience and connection with the natural world. By gazing up at the stars in "perfect silence," the speaker seems to find a deeper sense of wonder and mystery in the universe than what was offered by the astronomer's lecture.
Therefore, instead of specifically stating a geographical location where the speaker goes, the poem portrays a transformative shift in the speaker's state of mind and engagement with the world by transitioning from an enclosed lecture room to the open night sky.