Prime Echoes — The Tower

Prime Echoes are acoustic returns generated within the Tower that satisfy the three diagnostic criteria of Class Γ and are accordingly elevated to Class Γ-Prime under the practice recorded in Class Γ-Prime. Unlike ordinary reverberations catalogued in The Cabinet of Echoes, Prime Echoes are held to possess documentary weight and are transferred, pursuant to the standing arrangement between floors, from Floor 770 to Floor 440 the Gilded Aviary for further study. The subject occupies a contested position in Tower acoustics, as the Concordance Prime and subsequent recensions disagree on whether a Prime Echo may be cited as evidence in a dispute settled by Concordance.

Origination and Diagnostic Ascent

A Prime Echo begins as an unclassified return detected in any gallery, stairwell, or aperture. When the echo meets all three diagnostic criteria for Class Γ — sustained decay exceeding nine Prime Metres of corridor, intelligible repetition of a notarized phrase, and resistance to the Silence Edicts issued by Scriptorium Prime — it is elevated to Class Γ-Prime by the attending clerk of The Chamber of Receding Echoes. The original ninety-four leaves of Concordance Prime, inscribed with the Prime Stylus, prescribe that elevation be recorded in the Log of Initializations held by Scriptorium Prime on Floor 301. Surveyor-Prime Elara Vance observed in her winter survey of West Spiral 44 that "the ascent of a Prime Echo is less an event than a correction the floor makes to itself" (Surveyor-Prime Elara Vance, Field Notes, Vol. XII, p. 203). Her professional rival Surveyor-Prime Althea disputed this, holding that the ascent was administrative rather than acoustic.

Transfer to the Gilded Aviary

Upon elevation, Prime Echoes from Floor 770 are transferred to Floor 440 the Gilded Aviary for further study, where they are housed in suspended cages of untreated wire. The transfer is effected by carriers of the Librarian-Prime Anselm the Damp line, who are required to maintain a silence broken only by the echo itself. Internal measurements of cage spacing are given in Prime Metres, as governed by the Prime Metre Bar whose provenance is a matter of record assigned to Scriptorium Prime by the Fifth Concordance. A visiting rule of the Aviary states that no more than two clerks may whistle at once, to prevent the registration of a false Prime Echo.

Documentary Status and the Concordance Dispute

Whether a Prime Echo constitutes admissible record under Concordance Prime is unsettled. The Third Concordance, Annex 4, provides plainly:

"A Prime Echo elevated under Class Γ-Prime shall be received as transcript where the original utterance is lost to the Tower."
— Third Concordance, Annex 4

The Fifth Concordance, however, amends this by stating that "no echo, however prime, shall supersede a leaf inscribed by the Prime Inscriber" (Fifth Concordance, Clause 19). The contradiction has produced three recorded rulings of the Librarian-Prime reversing earlier Aviary citations, the most recent being the Hallow Recension of the 412th Interval. Scholars of the Scriptorium Prime maintain the Master Orthographic Table resolves the conflict by treating the echo as commentary, not text.

The Incident of the Double Return

In the 288th Interval, a Prime Echo on Floor 55 repeated the seal-phrase of Concordance Prime whilst that document was held under seal in the eastern alcove of Scriptorium Prime. The LLAS-001 was triggered when the echo then decayed beyond measurement, an event chronicled in Echoes in West Spiral 44. The Prime Inscriber filed a sworn affidavit, notarized by Scriptorium Prime, asserting the return had been "premature and not of this floor's making" (The Prime Inscriber, Affidavit 77-B). The matter was referred to Librarian-Prime but no concordant judgment was entered, owing to the loss of the eastern alcove key.

Scholarly Disagreement on Persistence

A further dispute concerns the persistence of Prime Echoes after transfer. The orthographic school of Floor 301 holds that the echo remains bound to its floor of origin, citing the Chamber of Receding Echoes as proof of residual attachment. The Aviary conservators contend that transfer severs origin entirely, a view supported by Surveyor-Prime Elara Vance in her dissent to the Hallow Recension. The Second Concordance is silent on the point; the Fourth Concordance is missing from the catalogue and presumed receded.