Mirror Atrium

Definition and Standing

The Mirror Atrium is a designation applied by the Tower to atrial sectors whose principal architectural feature is a reflective duplication of their own plan. It is a descriptive term of long usage and no fixed jurisdiction: at least fourteen atria currently carry the designation in whole or in part, and the Registry of Atrial Nomenclature records a fifteenth entry whose floor number has been illegible since the Annex of 712. In practice the phrase is used both for a single celebrated chamber and for the class of chambers resembling it, a double duty which the Chronicles of the Mutable Atrium has repeatedly urged the Librarians to resolve and which the Librarians have repeatedly declined to.

The term should not be confused with the architectural classification of Mirror-Stacks, which governs floors or sectors relying on symmetrical replication, optical recursion, or informational duplication. The Mirror Atrium is one instance of a Mirror-Stack; most Mirror-Stacks are not atria.

Location and Fabric

The chamber most commonly meant by the bare term lies between floors 640 and 651, though the intervening numbering, as is usual, resists reconstruction. Its floor is dark stone, its ceiling is not visible from any standing position recorded in the Fourth Concordance, and its four walls are of glass set in lead of an unusual grey. The glass does not show the room. It shows the room as it was at the moment of glazing, which is to say empty, swept, and lit from a single aperture that no longer exists.

Visitors are permitted to remain for a period of one hour, after which the attendant on duty is required to open the north door regardless of the party's wishes. The rule dates from the incident of the Long Viewing, during which a delegation from the Atrium of Authority remained inside for nine days and emerged with a report of the room that no subsequent party has been able to corroborate.

The Several Candidates

The Penumbral Atrium is frequently proposed as the true referent of the designation, on the grounds that its shadow-work constitutes a form of reflection. The Œdicentric Calibration Atrium disputes this, holding that calibration is not reflection, and that a mirror which corrects its subject is a mirror which has ceased to be a mirror. The Waxwell Atrium does not formally advance its candidature but has, on three occasions since 699, reprinted its own floor plan on the verso of every notice issued by any other atrium claiming the name.

The Echovoid Atrium was added to the list of candidates in 704 by Clerk-Registrar Halvern Siss, who argued that an echo is an auditory mirror and that the Tower's nomenclature should not be subordinate to optics. His annotation survives in the margin of the Registry. The Registrar who followed him struck through it twice and wrote "no" in a firm hand.

Disputes of Nomenclature

The principal scholarly disagreement concerns whether the Mirror Atrium is a place or a condition. The Verificationists, whose position on matters of surface and validity is well recorded in connection with the Mirror That Reflected Nothing, maintain that only a chamber with an actual reflective plane may bear the name. Against them, the Recursiveists — a faction arising from the fallout of the Schism of the Mirror Catalogue — hold that a room is a mirror of itself the moment it is catalogued twice, which would make most of the Tower a Mirror Atrium and would, they concede cheerfully, settle the matter of which chamber is meant by abolishing the question.

Concordance authority is, as ever, divided. Clause 303.b, invoked to decisive effect during the Schism, is cited by both sides. The Mirror Catalogue Protocol leans toward the Verificationist reading but stops short of naming a chamber.

"Let there be no dispute over the name where there is no dispute over the glass."

— Third Concordance, Annex 11

Incidents

In the winter of 707 the north wall developed a hairline fracture which, over the course of eleven weeks, reflected a crack in a wall of the chamber that was not there. Repairs were attempted twice by the Office of Surfaces and twice the repair was reflected as a patch on an intact wall. The matter was settled by Form 7a-B2: The Containment Mirror, which required the physical containment procedure to be mirrored in the document and the document to be mirrored in the chamber — a correspondence that took four months to satisfy and which no one has since troubled to withdraw.

Archivist-Notary Kael, whose work on Proleptic Resonance at the Mirror-Galleries of Floor 1173 is well known, surveyed the Mirror Atrium in 710 and concluded that the room reflected intentions rather than bodies. His report is filed, sealed, and available on request to any reader who can state, in advance, what they expect to see.

Access and Observances

Admission requires the countersignature of two officers of separate bureaux, a requirement introduced after the Schism as part of the general tightening around reflective holdings. Hand lamps are prohibited; the light of a lamp held near the glass is reflected at an intensity the attendants find wearing. Chalk is permitted on the floor but must be swept before departure by the person who used it. No one has ever been asked to sweep twice.

The Mirror Atrium is maintained under the general provisions applying to Mirror-Stacks and the corridor provisions of the Creation of Mirror Corridors. Its current designation, floor number, and candidate status are recorded in the Registry and revised, on average, once every eleven years.