Luminous Quarantine

Luminous Quarantine is the standing arrangement under which a subject whose light cannot be certified is separated from other holdings, enclosed, and observed until its emission either stabilises or is ruled permanent. It is the oldest of the Tower's quarantine regimes and the only one administered by two offices at once, a division of authority set out — imperfectly — in the Treatise on Luminous Quarantine and contested in every generation since. The Quarantine Authority holds operational charge of the separation itself; the College of Luminous Anomalies holds sole competence to rule on whether a light is present, which is not the same question as whether it is permitted.

Definition and thresholds

A subject enters Luminous Quarantine when its emission falls outside the band recorded on its baseline at the point of accession. The bands are not measured in absolute units; the Tower has never agreed on one, and the Standing Panel on Photometric Standards has been in recess since its eleventh session. Measurement is instead comparative, by the Twin-Mirror Method, which sets an unknown emission against the earliest known record of the same substance and reports the difference as a whole-number ratio.

Subjects below the threshold are returned to the general floors. Subjects at or above it are conveyed to the Quarantine Annex and entered in the Luminous Quarantine Ledger, which by the Treatise on Luminous Quarantine must be kept in Luminous Verdian ink on continuous rolls of Luminous Papyrus. The master roll is held on Floor 9,002 in a vault cooled by Luminous Mortar; the subsidiary rolls are kept in the carrel corridors and are replaced at intervals of nine years, not because they have failed but because the ink is understood to have finished saying what it had to say.

Phases and the Audit

Holding proceeds in three phases. Phase 1 is a blind carrel with a single aperture; Phase 2 permits a second observer and a reading lamp; Phase 3 requires what the Treatise calls "the luminal conditions proper to the third degree", which it does not specify. The Luminous Audit is the periodic examination of the whole quarantine population, at which each registered shadow is re-examined against its baseline and its departure recorded in the Ledger. A shadow that has entered the Audit and returned to baseline is released. A shadow that has not returned is not a shadow.

Phase 2 is ordinarily a matter of months. Phase 3 has been reached twice in the archive's record; one of those subjects was later found to have been an ordinary Phase 2 holding that had been entered in the Ledger twice, once under each of its two entrances. The carrier of the Ninth Corridor had been walking the same carrel for some eleven years before the duplication was noticed.

Disputed competence

The Concordance of 21 assigns the power to release a Phase 3 subject to the Authority, on the certificate of the College. The Concordance of 21 — which cites the earlier document as its own authority and does not mention the College at all — assigns it to the Authority alone. Both remain in force. The Quarantine Authority has resolved the difficulty by an internal practice, unrecorded in any Concordance, of obtaining the College's certificate and then filing it. The College has objected to this practice in writing fourteen times; the Eighth Memorial of the College of Luminous Anomalies lists the fourteen objections in order and notes, in the same hand, that the first has received no reply.

In the winter of a year the College dates to its own founding, the two offices were unable to agree on the release of a single subject in a Phase 2 carrel. The filing clerk, Amanuensis Vell, who had held the carrel's register for thirty years, kept the subject in the corridor for the duration of the disagreement and afterwards submitted a memorandum, refused at two levels, arguing that the memorandum should be regarded as the release. The Concordance of 21 was cited against her. She cited the Concordance of 4 in reply. The reply was never opened, and the carrel's aperture was thereafter sealed for reasons that the file describes only as "the arrangement of the corridor".

Instruments and the Ledger

Because the Ledger must remain legible in the dark common to quarantined carrels, and the ink is not, an observation is first recorded in the field and transcribed within the hour. The field instrument is the Luminous Quarantine Ledger's auxiliary tally, a slate of nineteen graded leaves, of which the first three are always blank. The blank leaves are not, as visiting scholars sometimes assert, a formal allowance for error; they are the underlay, and the fourth leaf is read against them.

The transcription is a point of genuine scholarly disagreement. The Quarantine Record, an older and plainer register, uses the word "duplicate" for an entry written twice, and the Concordance of 21 annexes the Luminous Quarantine Ledger to it as a matter of ordinary writing. The Luminous Quarantine Ledger, on the face of its own folio, calls the second entry a "witness", a term of art belonging to the Chamber of Luminous Calm and meaning an entry that has been copied in order to be checked. The two cannot both be right: a witness verifies an entry, a duplicate merely repeats it. The Standing Panel on Photometric Standards was asked to settle the question in its ninth session, and recessed.

Practitioners' customs

The Authority's carrel officers maintain a small body of usages that appear in no Schedule. An officer does not stand in the aperture of an occupied carrel while reading the tally, and the tally is not read aloud in the corridor. A shadow found within half a ratio of its threshold may be left to the following morning; a shadow found beyond it may not. The Quarantine Annex's standing instruction, posted in the antechamber, requires that the outer door of the annex be propped open during the delivery of the gelding carts, and again at the close of the Audit. The propping is a matter of the first leaf of the tally and the ledger is signed to that effect, in Luminous Verdian, in the second hour.

See also

• Quarantine Authority
• Luminous Quarantine Ledger
• Treatise on Luminous Quarantine
• Chamber of Luminous Calm
• Floor 9,002
• Material Quarantine