Considering the title , the intelligent reader asks himself when the poet heard the learn’d astronomer and what he felt in that moment. So he wants to read this poem because he wants to know it.

The poem is arranged in four stanzas : the first one of 3 lines(tercet)the second one of 2 lines, the third one of 2 lines and the last one of 4 lines (quatrain). Then the all lines begin with capital letter.

The first stanza, the second one and the third one begin with the word “When”, it is a anaphor. It is getting faster the reading and it adds rhythm to the reading. Then in the fist and second line there are two assonance of the letter “e”.

In the end the poet wants to tell when he fall in love for astronomy.