Pattern Isolation

Definition and standing

Pattern Isolation is the practice of restricting a catalogued waveform from contact with other waveforms of the same class, so that each may be read, recorded, and shelved without the interference of its neighbours. It is distinguished from the general practice of Isolation — which governs exposure of a holding to any other holding whatsoever — by its narrowness: Pattern Isolation concerns interference between distinct patterns and nothing else. A pattern isolated under this heading may still be consulted, handled, weighed, and discussed; it may not be permitted to resonate alongside another pattern within audible or instrumental range.

The practice is usually conducted under the three-stage procedure set out in the Isolation of Variance, with the second stage shortened by one day where the pattern's Isolation Interval has already been established. Where an aperture is involved, the procedure is entered only after the Ingress Amp Isolation Practice is complete.

Instruments

Pattern Isolation is worked with a Standard Tuning Fork, Pattern Gamma, which serves as the working reference in most spirals. Personnel walking between isolated patterns carry a Tuning Fork, Pattern 7 in addition to the Gamma fork, since the Gamma reference may not be struck while in motion without disturbing the pattern under isolation. Readings for pattern flattening are taken with the calibrated flattener of the Third Recension pattern; the Scholiast Pattern Resonator is not approved for use on isolated patterns and its presence in an isolation chamber requires written dispensation.

No fork of any pattern may be struck within two paces of a pattern under isolation unless the striking is itself the observation. Fork storage in isolation chambers is by rack, not pocket.

The winter of the Keel Floor

The practice acquired its present form after an incident on the Keel Floor in the winter of the year recorded in the floor register as 41-Rho. A junior clerk, Mira Selvane, had been assigned to catalogue nine waveforms recovered from a stairhead annexe and, finding the isolation chambers crowded, worked two patterns at a single bench. The patterns resonated. The resulting interference was audible on four floors above and two below, and was later found to have altered the readings of the Isolation Audit then in progress on the floor above, invalidating eleven entries.

Selvane's defence — that the two patterns had been entered in the bench register under separate numbers and were therefore, by her reading, separate holdings — was accepted as an argument but rejected as a fact. The ruling of the Commissioner's office, recorded as Annex 9 to the Protocol Alpha, holds that "a separation of record is not a separation of air" (Second Concordance on Interference, Annex 9). Selvane was reassigned to the bindery and is remembered chiefly for the two-metre bench spacing now standard in all isolation chambers, informally called Selvane's interval.

Relation to the catalogue

Pattern Isolation is recorded within Isolation Amp Cataloguing as a distinct sub-form; the observational rigour of that practice applies to any pattern read while isolated. Both the stabilising protocols of Ingress Amp Isolation Practice and the more general framework of Isolation and Quarantine are invoked when a pattern is found to have isolated itself, a condition first documented in the Wave-Pattern Thesis and termed by its author spontaneous seclusion.

The records office maintains that spontaneous seclusion is impossible and that the appearance of it arises only from mis-shelving. There is no agreed procedure for the appearance of it.

Disputed readings

The principal disagreement concerns whether Pattern Isolation is a species of isolation or of segregation. The Third Concordance holds that "isolation of pattern is isolation of the holding, pattern being the holding's whole account" (Third Concordance, clause 14.2). The Fourth Concordance rejects this in its annexe, arguing that a pattern's account is separable from its resonance and that Pattern Isolation therefore falls under Protocol Alpha, "the holding being untouched and only its ringing confined" (Fourth Concordance, Annex 3, clause 6).

"Where the pattern is silent, the holding remains; where the holding is removed, no pattern remains. The two isolation practices cannot be the same practice, being true of different things."

— Fourth Concordance, Annex 3, clause 6

Practitioners have generally ignored the question. The Isolation and Documentation committee notes that both readings produce the same bench, the same spacing, and the same paperwork, and that the dispute has therefore consumed forty-one years and no measurable quantity of arc-lamp oil. A third reading, advanced by the Office of the Commissioner for Harmonic Integrity, observes that the three recognised variants of prism — Pattern Alpha, Pattern Beta, and Pattern Theta — behave differently under isolation, and that the Concordances should not be asked to settle a matter that is properly instrumental.

Notable findings

Patterns isolated for more than one hundred days are recorded as drifting. The drift is not a change in the pattern but a change in the flattener's reading of it, first noted during the Recursive Infiltration of the spiral at aperture Sigma-3, and since confirmed on fourteen floors. Isolated patterns may not be isolated indefinitely without periodic re-reading against the Gamma fork, a provision added by the Fifth Concordance and routinely cited by no one.

Pattern Isolation has also been applied, in one recorded instance, to a Librarian. The Librarian was released after three days and the paperwork was filed under objects.