Penumbral Phase

The Penumbral Phase is the eighth and least tractable stage of the Penumbral Atrium intake sequence, during which a subject's partial substantiation is measured, attested, and — where the readings permit — provisionally fixed. It is distinguished from every other phase of atrium work by the fact that the subject is neither absent nor present, and by the further fact that the measurement itself alters the thing measured. Formal definition is carried in Ruling 712-A of the Chamber of the Fundamental Link, clause 6, which describes the Penumbral Phase as "the interval in which a subject may be counted but not yet weighed against itself."

Practice on the floor is governed by Penumbral-Gradient Index, the standing instrument for the phase, and the phase is conducted almost exclusively within Floor 1173. Its tribunals convene on the interstitial level known as the Atrium of Lapsed Mandates.

Sequence and duration

The Penumbral Phase follows Phase Beta: Examination and precedes Stillness Phase. Between them falls the reading of the index, customarily taken at three stations spaced along the Grand Ramp of Attrition, whose pitch has been a matter of intermittent complaint since the incongruity recorded there by a junior archivist in the winter of 1861. Duration is not fixed: Ruling 712-A allows the phase to run until three consecutive readings agree within one-quarter gradient step, a condition occasionally unmet for centuries. The longest documented Penumbral Phase, on record shelf 719-β-sigma, ran from 1402 to 1718 and was terminated by the death of the instrument rather than the agreement of the readings.

Subjects are housed during the phase in Speculative Shelving, whose compartments are fitted with dividers removed for the duration so that a half-present article may occupy the shelf it would occupy if complete.

Instruments and readings

The gradient index is read from a brass frame holding two reference slips, one marked as the subject's presumptive whole and one left blank. The blank slip is the subject's own contribution to the measurement and is never seen by the reader. Readings are entered in triplicate on the phase ledger; the third copy is sealed, unopened, and delivered to the Vault of Un-Truths under the customary assumption that a reading recorded three times has been recorded once too often.

"Let the third entry be sealed before the second is compared to the first, lest the comparison instruct the instrument."

— Eleventh Concordance, Annex 2, clause 14

Dispute over termination

Two schools contest the phase's proper end. The first, citing Ruling 712-A of the Chamber of the Fundamental Link, holds that a subject whose gradient stabilizes must immediately proceed to Phase Delta: Verdict, the terminal sub-phase of the Primary Phase, and that delay is an unlawful detention of a partly-existent thing. The second, associated with the administration of Penumbral Annexes under the Clean Page Doctrine, holds that the phase may be closed provisionally and the subject returned to the shelves unjudged, provided no one thereafter asks whether it is there.

Elara Sind, Warden of the Annexes, has vigorously contested the provisional reading, maintaining in her memorandum of 1889 that a subject released from the Penumbral Phase without a verdict returns to its shelf with a gradient one step lower and is in consequence "less present than when we began, and more expensive to fetch." The Chamber has not resolved the matter. The Concordance of Provision permits provisional closure; the Eleventh Concordance forbids it; and clerks have settled into the habit of citing whichever they reach first on the shelf, a practice the Librarians have declined to correct on the ground that it produces consistent results.

Recorded incidents

In 1903 a subject on Floor 1173 stabilized during the phase, was returned to the shelves by a clerk who had not read the ledger's third entry, and was subsequently catalogued twice under different gradients. Both catalogues remain in service. The incident is cited in the Post-Incident Review of that year as an example of what the review calls "a termination without a witness."

In 1974 a Penumbral Phase was extended by nine days because the reference slips had been shelved in the wrong order under the Re Mapping Amp Re Cataloguing Phase Iii and no one wished to be the first to say so.

Standing instruction

The phase is worked barefoot. The instruction appears without explanation in the standing orders of Floor 1173, and no one now recalls its origin; it is enforced by the porter. Reading of the gradient is otherwise conducted in silence, at the three stations, and in the order the stations are numbered rather than the order in which they are reached.