Floor 449 ("The Sighs of Unfinished Bridges")

Floor 449 ("The Sighs of Unfinished Bridges") was a numbered floor of the Tower, formally winnowed in Tower Year 12,114. It is the only recorded floor whose principal holdings consisted entirely of sound, and the only winnowed floor whose materials were transferred in their entirety to a single annex without loss of volume. Its name is retained in the register of floors despite the floor having been emptied, in accordance with Concordance 88, which holds that a winnowed floor keeps its name "until such time as the name itself is found to be surplus."

The floor occupied a single spiraling gallery, 402 paces in circumference, whose western parapet was derelict for the whole of its recorded life. At a sealed aperture on that parapet began the Conduit of Sighs, a duct of uncertain terminus that carried the floor's characteristic sound upward through the fabric of the Tower. Repairs to the parapet were attempted eleven times between Years 9,880 and 12,060; each attempt was abandoned before completion, and the Curatorium of Unfinished Likenesses has cited Floor 449 as standing precedent that an unfinished repair may itself be catalogued as a holding.

Character of the holdings

The sighs of the floor were of a particular kind, described in the surveys as "structural" — that is, produced not by persons but by the building, at points where a bridge had been begun and abandoned. Each sigh corresponded to a named structure in the Catalogue of Unfinished Bridges, and the floor's keepers maintained a concordance between sound and entry that ran to forty-one folio volumes, of which thirty-nine survive. The volume covering the bridges of the northward galleries has never been located; the Hall of Unfinished Inquiries has declined to open an inquiry into its absence, noting that the inquiry would itself be unfinished.

Acousticians of the Archive of Half-Sighs classified the sounds as instances of the half-sigh, though the classification was contested by the floor's own keepers. The dispute is recorded in a marginal note attributed to the Third Underkeeper of the floor, a clerk named Halvern Rees, who held the position from Year 11,302 to 11,401 and resigned it in protest at what he called "the annexation of our lungs by another department."

The Winnowing of 12,114

Floor 449 was winnowed by order of the Twelfth Concordance of Measured Weights, Annex 9, which found that the conceptual weight of the unfinished had become a tangible, catalogued thing and could no longer be permitted to accumulate unmeasured. The finding is unusually brief by the standards of the Annexes; it runs to a single clause and does not define "conceptual weight," a gap that has occasioned forty years of correspondence.

"That which has been begun and stopped leaves a residue, and the residue may be weighed, and having been weighed must be shelved."

— Twelfth Concordance of Measured Weights, Annex 9, clause 2

The winnowing took eleven days and required the sounding of the gallery in the presence of three witnesses, one of whom, by the terms of the catwalk provision then in force, was required to stand at the eastern entrance throughout and did so for nine of the eleven days. The sound inventory was concluded on the tenth day; the eleventh was given over to a spillage of approximately four minutes of unassigned sigh, which were recorded in the general register as "ambient." The materials were removed to the primary annex of the Catalogue of Unfinished Bridges on Floor 11,507, where they are maintained as a closed acoustic collection and consulted by appointment.

The Chamber of Unfinished Symphonies objected at the time, renewing a claim of jurisdiction it had historically asserted over sonorous bridges. Its objection, filed as a single sustained tone, was not admitted to the written record; Floor 14,734: The Gallery of Unfinished Symphonies carries a note of the grievance in its catalogue of disputed holdings.

The numbering dispute

There is no settled account of why the floor bore the number 449, and the two leading positions contradict one another directly.

The first, advanced by the surveyors of the Spiral Register and endorsed in that body's fourth recension, holds that 449 was assigned in the ordinary way and that the absence of the floor from every sequence between 448 and 450 is a consequence of those floors being vacant, not of any error. The second, maintained by the Office of Departed Numbers, holds that 449 was a borrowed number, assigned to this floor in error and never returned, and that the true 449 lies elsewhere in the spiral and has never been catalogued. The Office has produced a memo on the matter every decade since Year 12,009; the memos are identical.

A third opinion, never formally tabled but repeated in the stairwells, is that the number was chosen because 449 paces was the measured circumference of the gallery and that the coincidence was accepted rather than investigated. No document supports this. It is nonetheless cited more often than either of the official positions.

Access and present condition

The floor remains reachable by the western stair and is open to visitors during ordinary hours. The gallery is empty. The parapet is still derelict and the aperture of the Conduit of Sighs is still sealed, though the seal is inspected quarterly and has been replaced twice since the winnowing, on both occasions because it had begun, audibly, to fail.

Visitors are asked not to sound the gallery. The prohibition appears in the hand of the floor's last keeper on a card above the eastern entrance and has never been formally rescinded, and the Librarians have confirmed by minute of Year 12,131 that an unrescinded card remains binding until the card is removed. No one has removed the card. It is thought the card is the only thing that has not been finished here.