Radial Stacks

Radial Stacks are the spoke-aligned shelving arms by which a floor of the Tower is divided against its own centre. The term is descriptive rather than administrative: it records how an arm is built, not what it is called, who keeps it, or whether it counts as a room. Under the definitions issued in the Clarification on Radial Terminology (891.Δ), a radial stack is defined by its structural path — the line it traces inward from the outer wall — and is expressly distinguished from its administrative volume, which is assigned separately and may not correspond to the drawn arm at all. Practitioners of Radial Measurement describe this as the difference between where an arm goes and where the arm is said to go.

Radials occur on most floors from at least 140 to 1,900, though the count varies by floor and the variance has never been shown to follow a rule. Floor 308 is organized around forty-eight radial stacks, of which fifty-two radiate inward toward the Speculation Pit as the Western Radial Stacks. Floor 1117 is likewise arranged around its Inference Pit, with forty-eight radials, and the coincidence of the number has been examined by three successive committees without agreement as to whether it is a finding or a habit of the building trade.

Terminology and the 891.Δ Settlement

Before the Clarification on Radial Terminology (891.Δ), "radial stack" was used loosely in floor inventories to mean any arm carrying shelving, any arm longer than a pace, or — on at least one floor — a corridor that happened to be straight. The Clarification on Radial Terminology Document of 1,411 AT fixed the present usage for all subsequent returns. It did not resolve the older question of where a radial is administratively said to go; that was left to the clerks of 891.Δ, whose determinations are binding and, by common practice, are made without leaving the desk.

The consequence is a durable class of dispute in which a structural arm and its administrative volume lie in different places, sometimes on different floors. The Annex of Perpetual Review records one such matter, spanning the winter of 1,402 AT, in which a radial stack on the western face of Floor 308 was determined to end at a point two paces short of where the shelving visibly continued. A reader who followed the recorded volume fell into the recess described in the next section. The clerk who made the determination is named in the annex as Under-Clerk Mavren Osquith, and the annotation beside his name reads: "Returned the following spring; declined to re-measure."

Length, Recesses, and the Seven-Pace Rule

The Seventh Concordance governs the Western Radial Stacks and classifies arms of seven paces or fewer as recesses rather than stacks. The classification matters because recesses are not counted in floor returns, are not shelved to the outer face, and cannot be appealed against. The rule's simplicity is deceptive. Measurement of an arm in the western stacks properly begins at the inner face of the retaining wall and proceeds inward, but the True Azimuth of that wall has shifted by as much as nine degrees since the Concordance was sealed, so that an arm measured in one season may classify as a stack and in the next as a recess without a single board being moved.

The Division of Radial Measurement maintains that its classifications are of record and therefore cannot be affected by the movement of the building; a position restated in every annual return since 1,388 AT. Critics of the Division observe that the returns have been identical in their wording for forty years, including a typographical error in the date.

Construction and the Carnelian Incident

Radials are pinned to the outer wall before the floor's central aperture is cut, a sequence that presupposes a centre which is not yet there. The plaster and carnelian inlay of the older stacks is prone to lead rot at the pinned end, and the General Inventory of 1,260 AT records that 211 arms in the northern stacks were re-pinned in a single campaign. The same inventory carries a ground-floor notice inserted by the Parchment Ateliers of Sigma Spiral concerning footwear worn on the radial decks; it has been reprinted in every subsequent inventory without alteration.

In 1,337 AT a gang working the western stacks on Floor 188 hung a plumb line from the outermost bay and drove it through the arm, on the reasoning that a line dropped toward the centre would show them where the reach ended. It showed them instead that the arm had no end they could reach. The plumb was recovered; the bore was not, and appears on later plans as a slender void the draftsmen were instructed to leave unshaded. The incident is cited in the recension dispute of 1,344 AT, in which two scriptoria advanced incompatible accounts of whether the bore had been made before or after the centre was cut, and the matter was closed by sealing both accounts together in one rather than choosing between them.

The Migrating Map and the Western Degree

The Migrating Map was originally catalogued as a topographical representation of its western radial stacks, though Floor 188 is not Floor 308 and the map's own legend offers no comment on the discrepancy. A later hand has annotated the margin with what appears to be a walking count. Compared under the 891.Δ definitions, the Cygnet reach of the western stacks corresponds to administrative Degree 3, while the structural path on which it stands belongs to Degree 4 — a mismatch that the Division has been asked to reconcile on eleven occasions and has each time returned unopened.

Annex B of the Appendices now concerns the Radial Domain and permits a working party to proceed inward along a radial stack without first obtaining a bearing, provided the party is no larger than three. Parties of four have twice been refused, and in the second instance the refusal was recorded against the party's leader by name.

Holdings

Related records held on the radial stacks include the following, listed as they appear in the index rather than in any order of usefulness:

• Ninth Radial Quarry — arm head, extraction returns
• Form γ-7 — notice of recess classification, in triplicate
• Clarification on Radial Terminology Document — 1,411 AT recension, sealed
• Corridors Alpha through Epsilon — access to the western decks
• Cardio-ideogram Plates — consulted for arm-pinning diagrams

Readers are reminded that arms of seven paces or fewer have no entry in the index at all, and are to be sought by walking them.