Translumine-Δ (Material Specification)

Translumine-Δ (Material Specification) is the superseded technical schedule governing the formulation, casting, and archival acceptance of the material known as Translumine, issued by the Subscriptorium of Materials in the 121st year of the Consolidation and withdrawn from general circulation by the Consolidation of 12044. It is distinguished from the material itself in that Translumine remains in continuous use, whereas Translumine-Δ describes a standard to which no approved stock has conformed since the spring of 12046. The specification is retained in the active register for the sole reason that three hundred and eleven kilometres of Evaluated-Region conduit, and almost the whole of Photophobic Holdings below Floor 2200, were laid against its tolerances and cannot be recertified to Archive-Grade Buffer 7a without being opened.

Copies are held in the Glasswrights' Atrium, in the Subscriptorium's sealed annex, and in at least two private collections whose owners dispute the Atrium's claim to primacy of recension.

Content of the specification

The document runs to forty-eight leaves and is chiefly concerned with what Translumine-Δ calls attitude under load: the tendency of cast Translumine, when held at temperature for long periods, to drift not in dimension but in the direction it is understood to be facing. Earlier schedules had treated this as a defect. Translumine-Δ treats it as a measurable property and assigns each cast a drift allowance, expressed in milliradians per decade, written on the caster's ticket in red ink.

The schedule also fixes the trace-element envelope for the rhetorically-inert alloys that Translumine is customarily cut with at the time of casting, and specifies the anneal. It is silent, conspicuously and by its own admission, on the question of lamination. This silence is the subject of the whole of Section 6, which is a defence of it.

Drift allowances and the Clerks of the Solid

The Clerks of the Solid adopted Translumine-Δ as their working standard in 12029, principally for the gloves. A Translumine glove cast to the Δ allowance can be worn for an eleven-hour watch without developing what the Clerks call opinion — a faint but cumulative resistance at the fingertips, as though the glove had begun to disagree about the orientation of the hand inside it. The Conduit Specification had for two decades required gloves to be recast each watch; the Δ schedule made that recasting unnecessary and the Conduit Specification's authors have never quite forgiven it.

Subscriptor Vell, who compiled the schedule, records in his working notes that the allowance was set by trial on forty pairs of gloves and one hat. The hat was not specified for any purpose and does not appear in the final text. Vell's note for the ninth of Second Frost reads, in full: "Hat holds. Nobody will ask."

Lamination and the dispute with the Casket Office

The most durable disagreement concerning the schedule is whether Translumine-Δ authorises laminated Translumine. The Memory Casket Office holds that it does not, and has refused Caskets built to Δ tolerances since 12047. The Subscriptorium holds that it does, since Section 6 states that "the schedule shall not be read to constrain the assembly of stock already accepted under the attitude clause" (Translumine-Δ, §6.2). The Casket Office's rejoinder, reproduced in its Standing Note of 12048, is that §6.2 constrains nothing because it says nothing, and that a clause which constrains nothing is not a clause but a courtesy.

"We are asked to accept a specification which governs the material up to the moment it is joined to other material, and no further. Nothing in the archive is used up to that moment and no further."

— Standing Note of the Casket Office, 12048, §3

The dispute has been carried to the Recursive Boundary Definition twice and both times returned on the ground that the question is not one of boundaries.

Withdrawal and the 12044 Consolidation

The Consolidation of 12044 produced the canonical specification of Translumine and its successor, Archive-Grade Buffer 7a. The Consolidation's annex on supersession lists Translumine-Δ among the schedules "continued in force for existing work and closed to new". The wording has caused difficulty, since the Consolidation nowhere defines "existing work", and the Subscriptorium has taken the view — never successfully challenged — that any cast begun before the Consolidation is existing work however long it remains open. The longest such cast, in the Atrium's lower foundry, has been open since 12044 and is expected to close in 1340.

A minor but persistent irregularity attends the withdrawn copies. Article 14 of the Consolidation requires superseded schedules to be stamped on the first leaf. Of the eleven surviving complete copies, four are stamped on the first leaf, five on the last, and two on the recto of the caster's ticket bound in at the rear, which is not a leaf of the document at all. The Subscriptorium's archival note attributes the variation to "the haste of the withdrawal" and asks that it be overlooked.

Continued use and maintenance

Translumine-Δ remains the acceptance standard for all stock destined for the lower stairwells, the carrels lined with Translumine for procedural opacity, and the interlocking plates of the Crystalline Polyhedron of Autonomous Sorrow, which predate the schedule and have never been recertified to anything. Inspectors carrying the schedule are reminded that the drift allowance is measured from the cast date and not from the date of installation, a distinction which cost the Subscriptorium four hundred metres of conduit on Floor 1877 in the winter of 12055. The conduit was found to have exhausted its allowance before it was laid and has since been understood to face south.

Staff removing a withdrawn copy from the sealed annex must sign the register in ink, not pencil, and must leave the string on the tag.

See also

• Archive-Grade Buffer 7a
• Conduit Specification
• Material Reconciliation
• Material Anomalies
• Specification Ξ-114