The Spiral Stair

The Spiral Stair is a helical ascent of one hundred and eleven turns, terminating at a landing that has been surveyed eleven times and entered four, and is not a stair in the ordinary sense: it is the Tower's principal instrument of measurement, and has been since before the Fourth Concordance was first recensed. The staircase occupies the whole of the shaft between the Upper Approach and the landing designated Δ-19-SA.13.8.112, and is catalogued under that designation in the holdings of the Spiral Stair. It is not to be confused with The Quiet Stair, which shares its geometry but not its function, nor with the corridors of Eastern Stair, Gamma Corridor, which are architecturally adjacent and jurisdictionally elsewhere.

The Stair's peculiar standing arises from a property noted in every survey since the second: a climber who completes a turn and looks back finds the treads behind them counted differently than they were on the ascent. The discrepancy is small — one tread in ninety, on average — and remarkably consistent. The Librarians do not regard this as a defect. They regard it as the Stair working.

Function and calibration

Because the Stair's count drifts, and drifts predictably, it serves the Tower as a standard against which other measures are checked. A floor's spiral designation, a corridor's length, the depth of a sub-level: all are ultimately referred to the Stair and expressed as a fraction of a turn. The practice is old enough that its origin is disputed, but its administration is not: the Stair is calibrated annually, in the winter, by a party of not fewer than three Librarians, one of whom must descend rather than ascend so that the two counts can be reconciled at the foot.

Calibration is not without hazard. In the winter of the 8th Cycle, a calibration party under Archivist-Lieutenant Kael recorded a discrepancy of nine treads across a single turn and, resolving it in favour of the descent count, adjusted the reference length by four per cent. Every spiral designation above the Upper Approach was subsequently found to be short by that margin, and the correction took eleven years to unwind. Kael's account of the affair, appended to the Seventh Spiral Survey, remains the standard warning against preferring one direction of travel over the other.

"The Stair does not mislead the climber. The climber misleads the Stair, by insisting on arriving."

— Archivist-Lieutenant Kael, marginalia to the Seventh Spiral Survey

Anomalies and dimensional fatigue

The Stair's more serious irregularities — landings that open onto floors not otherwise reachable, turns that appear twice in succession, and a stairwell on the forty-first turn that is cold in a manner the Tower's surveyors describe only as "unaccounted for" — were for many years catalogued as faults awaiting repair. The position changed with Kaelen of the Unfinished Stair, who argued in the Treatise on Stair Integrity that such irregularities are the predictable consequence of long use, and are properly termed dimensional fatigue. Kaelen's argument carried, and the Chair of Spiral Integrity was commissioned to monitor the Stair and to report on its condition at each recension of the Concordances.

The Chair's reports are read aloud at the foot of the Stair on the first day of each cycle. Attendance is not required. It is, in practice, total.

Custody and the disputed wardency

Custodianship of the Stair was initially assigned, ambiguously, to the Warden of the Spiral Stair, an office whose de jure title and procedural duties survived long after its practical authority had been dispersed among the corridor administrations. The first to hold it, Wren of the Spiral Stair, had been a Clerk-Advocate in the Eastern Stair jurisdiction in the late 8th Cycle and understood better than most how a title could outlast its jurisdiction. Wren's tenure established the arrangement that persists: the Warden stamps research permits for the Stair and for adjacent sectors, including Floor 743, and in exchange the corridor administrations do not contest the Warden's ceremonial precedence at the foot of the first turn.

The arrangement has been tested. A disputed entity logged during the Seventh Spiral Survey — entered in the schedule as the Wren of the Spiral Stair, and never satisfactorily distinguished from the person of the same name — was claimed by the Warden as falling within the office's custodial remit and by the Archivists of the Silent Stair as a catalogued object. The Precedent of the Silent Stair settled the matter in favour of the Archivists on the narrow ground that the entity had been logged before it had been claimed. The Warden's office has observed ever since that logging and claiming are not the same act, and that the precedent rewards speed over right.

Jurisdictional claims

The Stair has been claimed, at various times, by the Sultanate of the Silent Stair, by the Empiricists of the Calibrated Stair, and by the corridor administration of Eastern Stair Spiral 14. None of these claims has been formally withdrawn. The Sultanate's claim rests on a reading of the Ninth Concordance, Annex 2, which assigns to the Sultanate "all silent ascents within the eastern quadrant"; the Empiricists' claim rests on the Eleventh Concordance, which assigns to them "all calibrated verticals" without defining vertical. The two annexes have never been reconciled, and the Concordance Reconciliation Office has twice declined to hear the matter, noting that it has declined before.

In practice the Stair is administered by whoever is standing at the foot of it. This is not a doctrine; it is an observation, recorded by Surveyor Ilm of the Third Recension and never successfully refuted.

Access

Climbing the Stair requires a stamped permit, obtainable from the Warden's office and valid for a single ascent or a single descent, not both. Parties of more than four must be accompanied. Footwear is removed at the first turn and may be collected at the last, though climbers are advised that the last turn is not always the last turn. The Stair is closed to survey during calibration and to everyone else during the reading of the Chair's report.