Chamber of Calibrated Certainty

Overview

The Chamber of Calibrated Certainty is a measuring hall situated on Floor 8,844, one of the small number of Tower chambers whose entire purpose is to house instruments for establishing the factual validity of a claim. It is administered jointly by the Realist School and the Office of Unfunded Certainty, an arrangement that has never been described by either body as satisfactory. During the Crisis of Divergent Empties the Chamber acquired a reputation it has not since shed: its instruments, presented with the same proposition in the same hour, returned readings that agreed with one another and not with the proposition.

Construction and Instrumentation

The hall occupies a circular plan 31 paces across, entered by a single door from the western landing. A raised plinth at the centre carries the principal instruments, of which three are regularly consulted: the certainty theodolite described in Guild Standard 114-Δ-7b, two Atmospheric Intent Meters transferred on loan from the Chamber of Calibrated Measures and thereafter never returned, and a secondary scale graduated in intervals of one two-hundredth of a unit whose name the register does not record.

The Chamber's founding instrument was the original certainty theodolite, which reads the junctural integrity of a propositions's parts against the local certainty gradient. Because that gradient is not constant between floors, the theodolite is recalibrated at each use against a reference taken elsewhere; by longstanding practice the reference is drawn from the baseline maintained in the Chamber of Calibrated Volumes on Floor 10,001. Two of the Chamber's three bays are therefore empty of instruments at any given hour and are best visited early.

The Crisis of Divergent Empties

The Chamber first enters the record on the eleventh day of the ninth month of Year 4,087, when a clerk named Ottiline Vey submitted a routine certification of an adjoining chamber's certainty. Vey had taken her reference against what she recorded as a buttress; the buttress was on inspection a temporary column, and the certification was struck. The incident is cited to this day in instruction on reference-drawing, and Vey's correction of the register — a single struck line and a marginal note reading "column, not buttress" — is preserved under glass in the eastern bay.

The Chamber's greater notoriety dates from the Crisis itself. The Realist School maintained throughout that the divergent readings were a fault of the instruments' reference chain, and pressed its challenge from its own Chamber of Calibrated Measures on Floor 14,112. The contrary position, held by the Office, was that the instruments were sound and the readings were correctly divergent. No Concordance settled the matter. Regulation 44-B: Contaminants of Certainty was amended twice during the Crisis and once afterwards, and the final recension is silent on which party it supports.

"That a Chamber should disagree with itself is not disorder; that it should disagree with the object measured is the beginning of a wider question."

— Omega Whisper, cited in the Office's Crisis memorandum

A Persistent Disagreement

Two readings of the Chamber's history remain current. The first, favoured by the Office of Unfunded Certainty, holds that the divergent readings were genuine and that the Chamber's instruments were the only apparatus on Floor 8,844 to report the Crisis accurately. The second, favoured by the Realist School, holds that the readings were an artefact of the reference chain and that the Chamber's results should be discounted by the same measure as its certainty coefficient — a correction the Office has never accepted and the School has never withdrawn.

The dispute has a physical consequence. The certification marks cut into the west jamb of the door, recording each successive recalibration of the theodolite, are cut twice on some dates and once on others, and no Concordance establishes which set is authoritative. Visiting parties are advised to consult the eastern set.

Access and Maintenance

The Chamber is open to certified readers on the fourth and seventh days of each week. The stair from the western landing is steep and unlit above the ninth step; lamps are carried by the duty clerk and are not to be brought into the central plinth area, as the flame disturbs the intent meters. Instruments are not to be leant upon. The floor of the eastern bay is uneven near the wall and has been reported for resurfacing since Year 4,091 without result; readers are asked to keep to the marked boards.

General upkeep falls under the Margin of Procedural Certainty, which provides that no measurement taken in the Chamber is valid until the attending clerk has signed both the register and the door-jamb tally. The requirement was introduced after a lapse in Year 4,079 in which a complete set of readings was recorded, sealed, and thereafter found to belong to a different chamber on the same floor.

Recorded Holdings

The following instruments and records are entered in the Chamber's inventory, exclusive of loans:

• The certainty theodolite, per Guild Standard 114-Δ-7b, recalibrated at each use.
• Two Atmospheric Intent Meters, on permanent loan from the Chamber of Calibrated Measures.
• The Crisis register, Years 4,087–4,099, in four volumes, the fourth incomplete.
• The Vey marginal note, framed, eastern bay.
• One lamp, brass, unserviceable since 4,094.

Requests to transfer the Crisis register to the Chamber of Calibrated Echoes have been refused three times, on the ground that the Chamber's readings cannot be understood outside the Chamber in which they were taken. The refusal is not appealed, and the volume remains where it was written.