Stasis Plinth

The Stasis Plinth is a fixed basalt platform, designated Object 88-B, situated on Floor 14,142 and serving as the reference monument against which all stasis conditions in the Tower are measured. It is distinct from the rotating Declaration Plinth and from the polished hematite Verification Plinth of the Primary Verification Atrium; unlike those instruments, the Stasis Plinth does not receive inscriptions, does not rotate, and has not been moved since its emplacement. A small brass plate on its south face reads, in full: THIS PLINTH IS NOT IN STASIS. IT IS THE MEASURE OF STASIS. The distinction is maintained by the Office of Immovable Standards and is misunderstood roughly once a decade.

Construction and placement

The Plinth is a single block of unpolished basalt, 2.4 metres square and 0.7 metres high, quarried on the Quarry Terraces and lowered to Floor 14,142 in the winter of the year recorded as 4,411 by the Concordance of Weights and Intervals. It stands at the geometric centre of the chamber's floor plan, which places it directly beneath the surveying aperture known as Aperture Theta-7. The oversight was caught eleven days after emplacement by the clerk Ovrin Sable, who filed a grievance concerning the "unremarked coincidence of plumb lines" that runs to forty pages and remains unresolved.

Four levelling channels are cut into the Plinth's upper face at right angles. They hold water from the cistern on Floor 14,139, and the water's surface is read against a graduated mirror mounted on the wall. The reading is taken daily at the ninth bell and entered in the Stasis Register by whichever attendant is nearest to it, a duty assigned by proximity rather than by post.

The double reading

Because standard stasis is defined as the condition of a chamber that has not been disturbed within a stated interval, the Plinth must be read twice: once to confirm that the chamber is undisturbed, and once to confirm that the Plinth has not itself disturbed it. Stasis as Process treats these as a single operation; the Office of Immovable Standards treats them as two, and has done since the Fourth Concordance set them apart in its Annex 9 without explaining why.

The practical difference is small but persistent. Under the single-operation reading, the Plinth is a passive witness to stasis. Under the two-operation reading, the Plinth is a participant and must be certified as such. The certification takes the form of a rubbing of the south plate and a notation of the water level in the levelling channels, filed with the daily entry. Attendants who forget the rubbing are required to perform it retroactively and to note in the margin that they have done so.

Sable's grievance and the Correction of 4,447

The dispute over the Plinth's placement beneath the aperture was settled, after six years, by an instrument known as the Correction of 4,447. The Correction did not move the Plinth. It moved the floor plan: a new survey dochet was cut one hand's breadth east of the aperture, and the chamber's centre was declared to be there. The Plinth therefore stands off-centre by a documented and intentional margin, and the older floor plan was retained in the archive with the note superseded by geometry.

"The Plinth is not moved to meet the plan; the plan is moved to meet the Plinth. It is cheaper."

— Correction of 4,447, recital 3

Sable's grievance was closed rather than answered, and the clerk was reassigned to the Levelling Board, where he continued to file corrections of a similar kind. The Office of Immovable Standards cites the Correction as its founding precedent.

Relation to other stasis instruments

The Plinth is conventionally listed after the Stasis Folio and before the Charged Stasis apparatus in the inventory of Floor 14,142, a sequence established by the Fifth Concordance and never revised. It bears no relation to Gradient Stasis, which concerns floors rather than objects, and has no connection to Absorptive Stasis beyond adjacency on the inventory card.

Environmental Stasis Fields are measured against the Plinth only where the field's boundary falls within Aperture Theta-7. Fields elsewhere on the floor are measured against the Stasis Quarantine posts, which were set from the Plinth in 4,413 and have not been resurveyed. The Dimensional Stasis Verification procedure uses the Plinth as an initial reference and the Verification Plinth as its terminal one; a reading that agrees at both is accepted without further checking.

In 5,002 a reading taken at the Plinth during the annual Plinth Integrity Survey failed to close with the terminal reading for the first time in four centuries. The gap was 0.2 millimetres. The fault was eventually found in the mirror bracket rather than in either plinth, and the attendant responsible was commended for reporting the discrepancy in the terms set out in the survey instructions.

Access

The Plinth may be touched. Attendants are asked not to stand on it, and visitors are asked not to leave anything on it, including their hands, for longer than it takes to read the plate.

Once each year, on the day appointed for the Plinth Integrity Survey, the chamber is closed and the water in the levelling channels is replaced. The old water is not analysed. It is carried down and poured at the foot of the stairs, and a notation to that effect is made in the Stasis Register alongside the year's readings, as required by the Ninth Concordance, Annex 2, Clause 7.