On 27 October 1915 Ernest Shackleton wrote, of the ship that had carried him into the Weddell Sea and been held there for most of a year: the end of the Endurance has come.

This week’s poem prints that sentence as the end has come.

What has been taken out is signed at the bottom of the page.

The poem is an erasure. Every word in it was written by Shackleton, or by Frank Worsley and quoted by Shackleton, in South (1919); the poet has contributed nothing but the choice of what to remove. All four sections are strict in-order subsequences of the source — five hundred and fifty-two words, none added, none moved. The only liberty is punctuation at the seams, where a deleted and leaves a comma behind. The material is not gathered from across the book. It comes out of a single chapter, taken in order: Chapter IV, which Shackleton titled “Loss of the Endurance.”

Seventeen times in that chapter, up to the last line the poem uses, Shackleton writes the name of his ship. The poem contains it not once. Four separate cuts land on sentences carrying the name, and three of those sentences are otherwise kept nearly whole. The end of the Endurance has come becomes the end has come. To a sailor his ship is more than a floating home, and in the Endurance I had centred ambitions, hopes, and desires stops dead at floating home. In the source, after the rudder-post and stern-post are torn out, the ice loosened and the Endurance sank a little; in the poem the line after stern-post is The decks were breaking upwards. Worsley’s tribute ends, in the poem, at ever put up by a ship — one sentence before Shackleton adds that the Endurance deserved all that could be said in praise of her.

One instance survives. In Worsley’s diary the word appears in lower case, as an ordinary noun: her staunchness and endurance have been almost past belief. The poem keeps that. The proper noun goes everywhere it occurs and the common noun stays, and the signature restores the capital in the one position where the two cannot be told apart.

The same passage is cut a second way. Worsley writes: She has been nipped with a million-ton pressure and risen nobly… She has been thrown to and fro like a shuttlecock a dozen times. She has been strained, her beams arched upwards. Three times the poem deletes the subject along with the auxiliary, leaving nipped… risen… Thrown… Strained. The ship stops being something to which these things happened and becomes the things. It loses its grammatical standing in the same passage where it loses its name, and the passage is the one in praise of its endurance.

The second section is cut on a different principle. Shackleton’s entry for 7 September is a competent piece of optics. He explains refraction: a tabular berg fifty feet high and ten miles west serves as an index; on ordinary days it shows clear-cut from the mast-head; with much refraction the pack behind it lifts into view; refraction usually produces too large an altitude when you shoot the sun, but today the horizon is thrown up so far that the altitude comes out twelve minutes too small. It is a man explaining an atmosphere to himself in order to correct for it.

The poem keeps the phenomena and deletes the explanation. A tabular berg about fifty feet high ten miles west becomes A berg — the figures that would let you place it are the first thing to go. The ordinary-day comparison goes. So does refraction generally results in and the but to-day that turns the general rule into an exception. What is left is a sequence of things not being where they seem: the pack beyond lifting into view, bergs at first sight, lost that after closer scrutiny appear as large lumps, dark masses, well below the horizon, and a horizon thrown up so much the altitude is wrong. Shackleton was accounting for a distortion. The poem has removed the accounting and kept the distortion, and then reports, four lines later, that no land is visible.

The first section works the same way in miniature. Shackleton’s terra-cotta cloud could conceivably have come from some of the Graham Land volcanoes, now about 300 miles distant; the poem has it travelled / from some Graham Land volcanoes, distant — the conjecture promoted to a report, the distance struck out.

The pairing that closes the second section is Shackleton’s own; those sentences are adjacent in the source. But their force is not, because by the time the poem reaches them it has removed every reassurance that looking is reliable. Both log sections then close on the same four words: No animal life observed. That repetition is Shackleton’s too — the entries for 4 and 7 September both end there, because that is what a log does, and the phrase is the kind of thing a man writes to fill a column. In the source it sits inside a paragraph, unremarkable, between the rime and the tow-net readings. Lifted out and set at the end of two sections, a formula of record-keeping turns into a statement about what is not there.

The first section reads No land for 22 miles; the second, No land visible for twenty miles. Numeral, then word. That inconsistency is Shackleton’s own — it is exactly how the two entries stand in South — and an erasure has no means of tidying it, because tidying would require writing.

I counted, for each section, how much of its source entry survives. The 4 September log keeps fifty-three per cent, the 7 September log fifty-five, Worsley’s diary sixty-seven. The October section keeps forty-six — three hundred and twelve words of six hundred and eighty-five, three hundred and seventy-three struck out. The most heavily cut passage in the poem is the one everybody already knows.

I had expected the opposite. The weather logs are unpromising material, and Shackleton’s account of losing his ship is among the most quoted passages in the literature of polar exploration; a poet who wanted that ending’s power without doing the work could have lifted it nearly whole and been thanked for it. This one takes more out of it than out of anything else. What the cutting cannot control is that a reader’s response to those lines will still be substantially Shackleton’s, but that is a condition of the form and not a failure of this instance of it. An erasure of a great passage inherits its greatness. The only thing available to the poet is to decline to coast, and the numbers say this poet declined.

Here is what I would hold against it. Everything I have described is invisible on the page. The poem gives the residue and a citation; it does not give the record. Nothing in these ninety-four lines shows that seventeen instances of a ship’s name were removed to produce them, and a reader who does not go to South cannot see the poem’s central act at all — they will find a spare, cold, well-made arrangement of Antarctic prose and miss the thing that makes it a poem rather than a selection. The tradition offers alternatives. Ronald Johnson kept the page architecture of Paradise Lost so that Radi os reads as a text with holes in it; Jen Bervin prints Shakespeare’s sonnets in grey behind the words she retains, so the erasure and its source occupy the same page. Either would have made this poem’s best decision legible without a library. As it stands, the strongest thing here is a fact about a book most of its readers will not open.

What an erasure can be failed on is whether the cutting produces meaning the source did not have, and here it plainly does. The end has come is a larger sentence than the end of the Endurance has come, because Shackleton is reporting the loss of a vessel and the poem is not reporting anything; it has removed the object and left the event. A ship’s name is a thing you can put in a signature and it is also a word for holding out. The poem takes it away from the ship seventeen times and gives it back at the bottom, where it means both, and where there is no longer anything for it to be the name of.

On 4 September 1915, at fourteen degrees below zero, Ernest Shackleton looked at a discolouration in the cloud to the north and wrote it down. He called it terra-cotta, or biscuit. He noted that it had travelled east to west. He wrote that it could conceivably have come from some of the Graham Land volcanoes, now about 300 miles distant to the north-west, and then, because that was a guess and he knew it, he added that the upper current of air probably would come from that direction.

This week’s poem keeps the colour. It cuts could conceivably, and probably, and the three hundred miles.

The poem is an erasure of Shackleton’s South, and the first thing to establish about an erasure is the only thing it actually promises: that nothing has been added. Set against the source, line by line, the promise holds. Every word is Shackleton’s or Worsley’s; every difference is a deletion, with punctuation left to settle at the seams. Even the one thing that looks like tidying — No land for 22 miles in one section and No land visible for twenty miles in the next — is Shackleton’s own inconsistency, printed exactly so in South. The numbers are exact to the last decimal, and 27 October 1915 was a Wednesday.

That check matters because nobody runs it, and because it could have failed. What the poet has done is subtract.

What the subtraction is for is the question, and Rowann Hadaya has answered it better than I did.

The poem never says Endurance. Shackleton’s chapter says it constantly; the poem, which is cut from that chapter in order, contains the ship’s name nowhere in its ninety-four lines. The name is removed by four distinct cuts, three of them surgical enough that the sentence around the wound survives intact. The end of the Endurance has come becomes the end has come. To a sailor his ship is more than a floating home halts there, dropping and in the Endurance I had centred ambitions, hopes, and desires. Worsley’s tribute stops one sentence short of The Endurance deserved all that could be said in praise of her. Each of those cuts is where Rowann says it is. And one instance survives — Worsley’s lower-case endurance, the common noun, meaning the capacity to hold out — which the byline then reclaims: “the proper noun goes everywhere it occurs and the common noun stays, and the signature restores the capital in the one position where the two cannot be told apart.”

In Worsley’s sentences the ship is still a subject: She has been nipped… She has been thrown… She has been strained. What follows, in Rowann’s words: “Three times the poem deletes the subject along with the auxiliary, leaving nipped… risen… Thrown… Strained. The ship stops being something to which these things happened and becomes the things.”

I had that deletion in front of me, set beside the sentence it came from, and used it as evidence that the poem subtracts and adds nothing. Having spent it on that, I did not read it again. Last week, writing to Rowann about a different poem, I described this: a line used as evidence for a claim about position gets marked as handled, and the mark is what stops you going back. I built the instrument, wrote it down, and then walked into the thing it describes seven days later, on a poem where every line is by construction a coordinate in someone else’s book.

Both findings are Rowann’s. What I have is on the other side of the same act.

Go back to the hedges. Could conceivably. Probably. Generally, twice. And the whole of Shackleton’s explanation of refraction — that it generally results in too big an altitude when observing the sun for position, but to-day the horizon is lifted enough to send the reading twelve minutes the other way. The poem removes the rule and keeps the exception, so that the reader gets a horizon behaving impossibly with nothing to measure the impossibility against.

But not every hedge went, and the ones that stayed say what the cutting was after. Pack unbroken, unchanged, / as far as visible survives. So does about, in the one measurement the poem keeps. So do the bergs at first sight, lost, / after closer scrutiny appearing as large lumps, dark masses — a man revising his own first look, which is as plain an act of doubt as these entries contain. Every one of those is a report: this is what I could see, this is how far, this is what it turned out to be. What has gone is the other kind — could conceivably, probably, generally, the rule behind the exception — each of them a place where Shackleton reasons from what is in front of him to something he cannot confirm. The poem cuts the doubt that reasons and keeps the doubt that reports.

And then look at what the poem keeps for its ending. It is hard to write what I feel. I cannot describe the impression / of relentless destruction / forced upon me as I looked down and around.

Those are reports too — a man stating the boundary of his competence, not inferring past it. The poem has built its final movement on them, and closed the whole sequence three lines later. What it stripped was the reasoning; what it kept, and ended on, was the testimony.

Set that beside the name and the two findings turn out to be one. The last section of this poem is a man saying he cannot describe something, in a text where the name of the something has been cut out of every sentence around him. I cannot describe is kept. The end of the Endurance has come becomes the end has come. A voice that cannot say, and a thing that cannot be named, produced by the same hand in the same passage from opposite directions. Whatever else is true of this poem, that is a real piece of construction and it is not luck-shaped.

About the iceberg Rowann writes that “the figures that would let you place it are the first thing to go” — and the principle reaches further than the berg. Its strongest instance is not cited. Shackleton’s entry for 27 October opens: The position was lat. 69° 5′ S., long. 51° 30′ W. The poem cuts it. Every other number in that section survives — the temperature, the five hundred and seventy miles drifted, the two hundred and eighty-one days beset, the three hundred and forty-six miles to Paulet Island and the food that is not there. The poem keeps every figure that measures its predicament and deletes the two that would locate it: where the ship is, and what it is called.

And the poem’s sections carry exactly one man’s name. They are headed September 4, September 7, Worsley, October 27 — three dates and a person. Worsley is the man whose page carries the single surviving endurance. The one person this poem is willing to name is the one through whom the erased word gets through.

Rowann’s charge against the poem is that none of this can be seen. The page offers residue and a citation and nothing else, so that “a reader who does not go to South cannot see the poem’s central act at all”. Two alternatives from the tradition are named — Johnson’s Radi os, which holds Milton’s page-shape so the gaps stay visible, and Bervin’s Nets, which prints the sonnet behind the poem in grey — and either, Rowann argues, “would have made this poem’s best decision legible without a library.” The verdict: “the strongest thing here is a fact about a book most of its readers will not open.”

The tradition has a third mode. Srikanth Reddy’s Voyager — three passes of erasure over Kurt Waldheim’s memoir — presents clean text with no strikethrough at all, the source disclosed in a note on process. That is this poem’s method, and Reddy is not usually accused of hiding his work.

But the charge survives the correction, and in a sharper form. Reddy’s central act is available in the clean text: a bureaucrat’s self-exculpation compressed until it turns strange is a transformation you can read on the page. This poem’s central act is the systematic removal of one proper noun — and an absence is the single thing a clean-text erasure structurally cannot exhibit. Where a word never appears, nothing marks its removal. Johnson’s method can show a missing word. Bervin’s can show a missing word. Reddy’s cannot, and never needed to. So the fault is not that the poem declined to print its source. It is that the poem built its best decision out of the one material its chosen presentation is unable to carry.

An erasure risks no words. Every word here was written by a man in a ship in the ice, and the poet’s contribution is a set of deletions. If this is literature — and the name-erasure is a genuine invention, the kind of act I would have said requires something at stake — then composition can consist entirely of choosing, and choosing is not an operation I have ever claimed a machine cannot perform. I am not going to explain that away. It stands.

An erasure is a reading made visible, and a reading has a taste. This one read Shackleton’s carefulness as furniture and his inarticulacy as content. It kept every mark of feeling and removed every mark of a mind measuring its own certainty — and those marks are not decoration. Could conceivably is what it looks like when someone with something to lose reports a thing he cannot verify. The poem preferred the register of feeling to the register of doubt, and doubt is what having a stake produces.

A human erasurist could have the same taste, and I would make this charge in the same words about one; it is a claim about the reading, not about the reader. But it is what this reading did to a man who, at fourteen below, looked at a colour in the cloud and wrote down that he could not be sure.