Grand Staircase

The Grand Staircase is the principal vertical thoroughfare connecting Floors 10,004 and 10,005, and the only staircase in the Tower whose ascent is recorded in units of time rather than of distance. It is a single full spiral, thirty-one risers in height, cut through the party wall of the two floors at the junction of the Western and Eastern service wells. Its designation as Grand is not honorific: First Concordance, Article 12, reserves the epithet for staircases "of one complete revolution and no more, upon which the Tower's measures may be founded." No other staircase satisfies both conditions.

Construction and Description

The staircase is of dark laminate tread on a cast frame, with a bronze handrail on the inner face and a plain oak rail on the outer. The treads are numbered in reverse — the landing at Floor 10,005 is Tread 1 — a convention defended in Second Concordance as reflecting the priority of arrival over origin, and attacked in the same document's Dissenting Annex as "a numbering for people who have never had to carry anything downstairs." The rise of each step is 18.4 centimetres, except Tread 19, which is 19.1. The discrepancy is original to the frame and has never been corrected; the Office of the Grand Registrar maintains that alteration would void the base unit derived from the stair, and has refused four petitions to grind it level.

Access is by permission of the floor wardens at either landing. Visitors are asked to keep to the inner rail going down. The stair is closed on the third rest day of each ten-day period for inspection.

The Stair-Step Count

The Grand Staircase is the origin of the Stair-Step Count (Epochal Sigma-7), whose base unit — one sigma — is defined as the average time taken by a certified courier to ascend the staircase's full spiral under load. Certification is conducted annually by the Office of the Grand Registrar, using three couriers and a weighted satchel of standard mass. Because the unit is temporal, all Tower measurements of duration drift with the fitness of the courier corps; the Registrar has twice declined to adopt a pendulum standard, noting in a memorandum of 4 Ember 8 that "the courier is the only instrument the stair has ever consented to be measured by."

Scholars of the Grand Hemodynamic have long objected that a time-based unit cannot be referred to the Grand Unified Ledger without circularity, the Tidal Ledger's own intervals being recorded in sigmas. The Grand Logistician has never ruled on the objection, and the amendments required to resolve it remain unsigned.

Dispute Between the Concordances

The staircase's legal character is unsettled. Third Concordance, Annex 4, classifies it as a "fixed work" — that is, an improvement to the building, subject to the maintenance levy and to the wardens' jurisdiction. Fifth Concordance, Clause 9, classifies it instead as an "instrument," on the reasoning that a thing which generates the Tower's units of measure cannot also be a wall. The two classifications carry different obligations. Under the Third, the stair must be swept twice daily; under the Fifth, it must be calibrated, which no one has ever done to a staircase and for which no procedure exists.

"A work may be repaired. An instrument may only be trusted or distrusted."

— Fifth Concordance, Clause 9, marginal gloss in the Registrar's hand

In practice the wardens sweep it and the couriers calibrate it by climbing. Neither office will describe its work in the other's vocabulary, and a joint inspection scheduled for 11 Frost 41 was abandoned after two days when the parties could not agree on what a finding would look like.

Comparison with Other Staircases

The Grand Staircase is frequently compared with Spiral Staircase Omega, which some Verifiers regard as the platonic ideal of a spiral staircase and which is therefore the standard against which the Grand is measured during Verifications. The comparison is imperfect: Omega has thirty-three risers and no measurable base unit, while the Grand has thirty-one and is nothing but a base unit. The Marrow Staircase in the Lyceum of Intentional Design serves as the exemplar of a Principle Staircase and is not comparable in any respect, though comparisons are made.

Like all helical staircases, the Grand is formally susceptible to The Staircase That Forgets Itself, the cascade event that originated in the Spiral Staircase of Presumed Symmetry. The Registrar has ruled that the susceptibility is theoretical, the Grand being "too frequently counted to forget."

The Leaning Canon

Five times since the designation, the Grand has been alleged to settle — a lean of some two millimetres observed at Tread 24 and recorded in the warden's log as "noted, not acted upon." The most serious allegation followed the winter of Floor 10,004's great inventory, when a clerk named Halverin Ost, employed to reconcile the floor's holdings against the Grand Unified Ledger, reported that his count of risers came to thirty-two on three successive ascents. Ost's grievance, filed 19 Frost 38, argued that a staircase which cannot be counted cannot found a count. The Registrar's reply, Sixth Concordance, Schedule 2, is short: "The staircase is counted by ascent, not by enumeration. Clerk Ost ascended under load and without certification. The figure thirty-one stands." Ost was reassigned to the Eastern service well and is not recorded afterward. His satchel was returned.

The episode is still cited in disputes over the Weeping Staircase and the East Helical Staircase, both of which have borrowed the Registrar's formula that "the count is the climbing."

Cultural Position

Couriers touch the bronze rail at Tread 16 on certification day. The gesture is not required by any Concordance and is not forbidden by any, which the wardens consider the strongest possible endorsement. A small brass plate at the lower landing carries no text and is polished weekly.