Somebody is making a tremendous sound, and Hopkins goes searching through the natural world for something big enough to compare it to. The opening question is knotty, but its logic is simple. What being in "rank-old nature" could have existed earlier as the original of this "breath" that now, "here personal," rings out "these heart-song powerful peals"? The poem never says what the breath is. Judging by "personal" and "heart-song," it seems to be a human voice or music, so the poem becomes a hunt for a match in nature, with each candidate more thunderous than the last. The idea at its centre is that a human sound can be so overwhelming that only the sea, or a trumpet, will do as a comparison.
The first candidate is a wave, and Hopkins gives it a face. It is "a bush-browed, beetle-browed billow," a crest that hangs over like a scowling, shaggy eyebrow. The b sounds pile up in the line so that the words themselves seem to swell. Then the weather arrives: "a soúth-wésterly wínd blústering," with a tide that "rolls reels / Of crumbling, fore-foundering, thundering all-surfy seas in." The chain of -ing words acts like the sea. Each one rolls into the next, and "crumbling" and "fore-foundering" make the wave collapse forward as we read. Compounds like "fore-foundering" and the adjective "all-surfy" look like Hopkins's own inventions. They show him bending English to fit the noise, since ordinary vocabulary would not be rough enough.
The line "rolls reels" is a small pleasure in its own right. The two words share a sound, and they suggest both rolling and a staggering, spinning motion, like a dance or a spool unwinding. The sea is both violent and rhythmic, which suits a comparison with song.
The surprise is the last image. After all that thunder, the poem turns to what can be "seen / Únderneath, their glassy barrel, of a fairy green." The wave is a roaring mass from above, but inside the curl it is smooth, translucent and almost delicate. The word "fairy" is startling next to "thundering." The comparison now covers more than loudness, because the voice seems to hold both force and a strange clear beauty. The rhyme helps. "Been," "seen" and "green" echo each other across the passage, and "peals" and "reels" chime in the middle. The rhymes feel less like a fixed scheme than like waves breaking at uneven intervals.
The rhythm is heavy and crowded. The lines are long, and the stress marks in the text (they appear garbled here) seem to flag where the weight falls. This fits the sprung rhythm Hopkins is known for, where the count of stresses matters more than the count of syllables. Stressed syllables bunch together, as in "bush-browed, beetle-browed bíllow," and the line has to slow down to carry them. Short lines such as "A bush-browed, beetle-browed bíllow is it?" sit between the long ones like a pause for breath before the next surge.
Then the poem stops. A row of dots marks a gap, and the text resumes with another candidate: "Or a jaunting vaunting vaulting assaulting trumpet telling." The stacked words rhyme in pairs, jaunting with vaunting and vaulting with assaulting, so the line sounds like a fanfare. It ends on "telling," with no object and no verb to complete the sentence. As it survives, the poem is unfinished, and it ends in mid-search. "Telling" also echoes "tells off" in line two, which brings us back to the question that started everything.
What makes this fragment worth reading is how openly it shows Hopkins at work. The writing has the feel of a first attempt, with a mind trying out images and rejecting them. The sense of sound is also unusually physical. The wave's frown, its crash and its green inner light are all packed into the words. The poem does more than say that a voice is powerful. It piles up consonants and heavy stresses until the reader's own mouth feels the effort.