Content: The distance between his outstretched hands - he needs two people to measure anything larger than this. It is a small distance, which suggests is still importanr to him.
"the acres of the walls, the prairies of the floors."
Extended metaphor - language about measurement - represent the changing relationship between the mother and narrator. The growing size of the distance represents the movement away between parent and child. Could be a child like representation of the distance between them.
Structure: two single word sentences. Both with strong imagery relating to being supported or possibly restricted. Symbolic of the relationship between mother and child.
Language: imagery relating to parent, child imagery and the support needed. Metaphor for language related to adventure and excitement, as well as fear in regard to the unknown.
Structure: ellipsis could represent the dots at the end of thd tape measurerer. Or it could suggest that his mother finally lets go of the tape and therefore him.
Language: imagery of the narrator wanting to move away. "Hatch" suggests bird imagery and of flying the nest. He is breaking free of his mother's protection, but does not know if he will succeed without her security and support.
Language: imagery showing that he feels there is no limit to the opportunities open to him / they can't be measured like the walls. Optomistic tone, in contrast to the final line.
Simon Armitage born 1963 in West Yorkshires. Part of a collection called 'Book of Matches'. Poems designed to be read in thr time it takes to burn a match.