This problem is old and has been solved repeatedly, in fiction and outside it. What follows is what other people did, what it cost them, and whether it transfers.

Already in this project#

The geographic coordinate system is the solution, and the prose is not using it. It already establishes everything needed: axial north–south fixed by the right-hand rule on the rotation vector, circumferential east–west with east running against the spin, and a level coordinate replacing altitude. It is unambiguous, it is in-world, and inhabitants would have grown up with it.

Of the six renderings in Dawn at Scimitar Falls, exactly one reaches for it: KSR’s “along its spinward curve.” Everything else navigates in imported Earth vocabulary. The coordinate system is not a missing solution; it is an unused one.

In published fiction#

Arthur C. Clarke, Rendezvous with Rama. The closest prior art there is — the whole novel is the problem. Clarke’s method is dedicated nomenclature applied relentlessly: named stairways, the Cylindrical Sea, north and south defined by rotation, and a narrator who will stop and re-establish the geometry whenever it matters. It works completely. The cost is that it reads as a guided tour; the prose repeatedly pauses to teach, which is exactly what the scene prompt’s “inhabit the givens; do not explain them” forbids. Clarke could afford it because bafflement at the geometry is his plot. Ours is not.

Larry Niven, Ringworld. The arch overhead is always present, in nearly every outdoor scene, as a visual fact rather than an explanation. The reader learns the shape by seeing it repeatedly instead of being told it once. This transfers cleanly and cheaply: the overhead is the single most orientation-dense object available, and mentioning what is up there costs a clause.

Kim Stanley Robinson, 2312 and Aurora. Terraria and generation ships rendered by a narrator who knows the engineering and reports it as ordinary fact — numbers, rates, systems. Orientation arrives as technical specificity rather than as description. The KSR voice page already identifies this. It transfers, with a caution: it only works in voices that tolerate an informed narrator, which rules out the Wolfe register entirely.

Ursula K. Le Guin. Orientation through inhabited practice — you learn a place’s shape from how people move through it, which paths they take, what they call things, which way they face to do ordinary work. The most elegant of the available methods and the least intrusive, because the orientation rides on characterization. It is also the least checkable: practice-encoded geometry is hard to audit, and the Le Guin rendering’s ambiguous “pull at them from the west” is what that weakness looks like.

J. R. R. Tolkien. The relevant lesson is not stylistic. Tolkien maintained consistency across a long work by keeping external artifacts — maps, and day-by-day itineraries reconciling distances against a calendar. The consistency was not held in his head; it was written down beside the draft and checked against. This is the single most transferable idea on the page, and it is the basis of The Spatial Ledger.

Gene Wolfe. A genuine alternative: make the unreliability diegetic. A narrator who does not understand the geometry can describe it wrongly and the text stays honest, because the error belongs to the narrator. The Wolfe rendering does this deliberately — “I had been told that the water descends in a curve … I had accepted this as I had accepted other things.” It is a real solution and an expensive one: it spends reader trust, works only in first person, and cannot be applied retroactively to errors you did not intend.

Outside fiction#

Nautical convention. Ships face the identical problem — a vessel has no compass-stable local directions because it turns — and solved it centuries ago with a body-relative frame: fore and aft, port and starboard, windward and leeward, above and below decks. The terms are precise, unambiguous, learnable in a page, and they survive the vessel changing heading. Readers of O’Brian or Melville absorb them without instruction. Spinward and antispinward are the same move, and the fact that the vocabulary is unfamiliar is not an argument against it — port and starboard were unfamiliar once too.

The 180-degree rule. Film’s answer to the same problem: an imaginary axis is drawn through the scene, the camera stays on one side of it, and crossing it flips the audience’s spatial map. Two things transfer. The first is the rule itself — pick an axis and stay on one side. The second matters more: film treats this as a hard constraint enforced by a dedicated role, not as a matter of the director being attentive. Continuity is a job because it cannot be done from memory while doing the other job.

Kevin Lynch, The Image of the City. How people actually build mental maps of a place: paths, edges, districts, nodes, landmarks. Lynch’s finding is that legibility comes from a small number of strong, repeated, unambiguous landmarks rather than from completeness. Coriopolis has the ingredients — the falls, the gap-sky, the overhead, the city up-axis — and mostly fails to use them consistently, which by Lynch’s account is worse than not having them.

What transfers#

Ranked by benefit against cost in this project:

1. The external artifact (Tolkien, film continuity). A written record beside the draft, checked mechanically. Cheap, unglamorous, catches everything in the audit.
2. The existing coordinate vocabulary (nautical, and already canon here). Free — it is written and unused.
3. The persistent overhead (Niven). One clause per scene, high orientation density.
4. Practice-encoded orientation (Le Guin). Best prose, hardest to verify. Use it, but do not rely on it as the only record.
5. Diegetic unreliability (Wolfe). Powerful, voice-restricted, and not a substitute for knowing the right answer.

What does not transfer is Clarke’s explaining narrator, which is ruled out by the project’s own constraints.