The Oven Bird
Spring-to-summer ratio
The bird measures decline mathematically: mid-summer is to spring as 1 to 10. Frost uses arithmetic to make decay precise and undeniable, not romantic.
Highway dust image
This shifts from natural observation to human intrusion. The dust signals civilization encroaching on the woods—the bird's world is being covered, polluted, diminished.
The bird's paradox
The oven bird doesn't stop singing despite knowing summer is ending. 'Not to sing' means knowing when *not* to sing—restraint, not silence. This is the poem's central tension.
The central question
The bird 'frames' the question 'in all but words'—it exists as song, not speech. The poem ends without answering it. We're left with the bird's unresolved dilemma.