When I heard the learn’d astronomer - analysis 

When I heard the learn’d astronomer

1 When I heard the learn’d astronomer, 

2 When the proofs, the figures, were ranged in columns before me, 

3 When I was shown the charts and diagrams, to add, divide, and measure them, 

4 When I sitting heard the astronomer where he lectured with much applause in the lecture-room, 

5 How soon unaccountable I became tired and sick, 

6 Till rising and gliding out I wander’d off by myself, 

7 In the mystical moist night-air, and from time to time, 

8 Look’d up in perfect silence at the stars.

Just considering the title the intelligent reader may be curious about what the poet heard from the astronomer and what happened after that, since the poet use when like something happened after his conversation.

The poem is arranged into 1 stanza of 8 line. Each line start with a capital letter and end with a coma.

The repetition of the word “when” at the start of the first, second, third and fourth  line make them look like a list of what the poet did and learned by the astronomer. 

The poet saw the evidences that the astronomer finds and uses for his speech. 

He saw the scientific part of the astronomer’s works.

The sixth line represents the consequences of what did the poet saw and learned from the confront with the astronomer, he felt exhausted to the point that he felt in his thoughts.

He forgot all the scientific skills that the astronomer told to him and just consider the sky and stars as the mystic creature they are. 

This poem what to focus the reader attention to how the scientific knowledge become irrelevant in front of the magnificent of the creation.