Locus Resonantis

The Locus Resonantis is a certified class of Locus reserved for subjects that cannot be said to occupy a fixed position at all, but rather a fixed reverberation — a standing pattern of return that the tower measures instead of a place. It is distinguished from the Static Locus in that nothing at a Locus Resonantis is still; it is distinguished from the Dynamic Locus in that nothing there travels. What holds is only the frequency, and the frequency is treated as the address. The class is maintained on the register of canonical locus types kept by the Office of Taxonomical Purgation, and it is the class under which Floor 743 is certified as a Locus Resonantis – Class Gamma (Static-Harmonic).

Definition and classification

The class is divided into four grades, defined in the Eighth Concordance on Acoustic Integrity, Annex 2:

The Gamma grade was introduced by the Eleventh Recension of the Locus Registry on the recommendation of the acoustician Mira Vell, who observed that several of the lower floors were returning the same subject obediently at a distance, but never more than two corridors over. Vell's recommendation, that a subject which cannot leave its own gallery without a guide has been anchored by its echo rather than its place, is the working origin of the entire class.

The certification of Floor 743

Floor 743 was certified on 12 Maeris 1142, under the authority of the Eighth Concordance on Acoustic Integrity, following an inspection by the Guild of Resonant Surveyors that had been requested twice in the preceding year and answered once. The surveyors found the floor's subject to be a middling grey tone, sustained with a faint periodic drop that the surveyors' instruments left unexplained. They noted that the gallery had been measured at 14 metres and had returned the same reading whether or not the surveyors were standing inside it, a result the surveyors found "unobjectionable but not encouraging" (Guild of Resonant Surveyors, Report 74). The floor's classification has been left undisturbed since, though the noise itself has been entered at the Central Archive under the provisional identifier Resonans 743-K.

Dispute between the Concordances

The principal dispute concerns whether a Locus Resonantis is a locus at all. The Fourth Concordance on Locus Description recognized only three canonical types, and defined a locus as a position at which a subject could be reliably found, and the class of the Resonantis does not appear in that document. The Eighth Concordance on Acoustic Integrity, forty years later, asserts a fourth class in Annex 2 — without mentioning the earlier four — and the Second Recension of the Locus Registry never reconciled the two. The Concordance on the Interpretation of Concording Instruments settled it in the ordinary way: ordinances never revised, and the more recent instrument prevails. The Fourth Concordance has not been changed and is likely to remain so.

Cardinal-Archivist Peln, writing in 954, took the stronger view, recorded in the margins of the Locus of Cessation ledger, that a subject that only vibrates, and has never once been seen to move, is under the Fourth Concordance simply not found: "A thing that does not travel is not an inhabitant, and a thing that does not rest is not a position." The Office of Taxonomical Purgation replied that the late Cardinal-Archivist's opinion, though notable, had never been certified, and the class continued to be applied to the floor from its certification to the present. The office has declined to re-argue the matter, saying that the cardinal's words are now preserved.

Monitoring and drift

Because the certified position of a Locus Resonantis is a frequency rather than a gallery, surveyors log the subject twice each year: once at its certified Primary Locus and once at any Secondary Locus it is heard from. Unlike the registry's ordinary subjects, the Resonantis drifts more easily than most, which is why an unusual note is owed to all Echo-Locus Drift on the floor. On 14 Bruma 1181 the surveyors recorded Floor 743's tone at gallery 11, 140 metres from its certified position, and found it had remained there for the better part of three weeks, the drone causing a slight but persistent swaying in the expedition's lamp-cage. The survey was repeated at the certified locus; the sound was not found there. The drift was entered as an ordinary measurement artefact and no notice was taken. The surveyors' return record notes only that the lamp-cage was found to be standing.

Proceedings and citations

Where the Locus Resonantis is cited, it is cited by grade and, where the instrument allows, by frequency. The eighth wardens' recent certification of the north stairwell, in the closed file of Locus Sonorus, calls the class in support of both sides of the question of whether a resonator can be a place of conclusion. As a rule, in the case of the Locus of Cessation, the Locus of Conclusion requires only a stationary event of the Cessation class and does not require a still one, although a Locus Resonantis may only serve as a Locus of Conclusion if the sound produced at the moment of Cessation is recorded in the same measurement as the event. Two figures of the Final Catalysis have been held in this class since 1173, which is also why they are never done near the establish. Where an instrument's readout cannot be equally certified at two stations, the certification may be refused. Once read, the Locus Resonantis is certified and enquiries may be directed to the office. Visitors to the certified floor are asked to keep their voices down; the echo carries the length of the gallery.