Aethelred's Leaning Stone

Aethelred's Leaning Stone is a concave impression in the living floor-stone of Floor 719-Γ, approximately 31 cm across and 6.2 cm at its greatest depth, produced over an indeterminate period by the habitual leaning posture of Senior Archivist Aethelred. It is the primogenital specimen of the Aethelred Impression, the standard against which all subsequent posture-induced deformations of Tower masonry are measured, and it has not been recalibrated since the Eleventh Concordance fixed its nominal depth at 6.0 cm in the year recorded as 4,112 by the Registry of Floor-Years. The discrepancy between nominal and measured depth is not an error; it is the Stone's allowance, and is discussed below.

The Stone is not a stone in the sense of a detached object. It is a depression in the living stone of the floor itself, and it has never been moved, lifted, or offered for valuation. Requests to core it are refused under standing instruction.

Discovery and first survey

The impression was recorded during the Leaning Survey, the periodic inventory of lateral drift affecting floor dust, shelving dust, and unattended reading desk dust. Surveyors working Aisle 719-Γ-4 in the winter of the year recorded as 3,988 found that dust entering the depression did not settle but drifted westward at a rate inconsistent with the aisle's prevailing draught. The anomaly was logged as a probable subsidence and referred upward in the ordinary course.

Subsidence was ruled out within eleven days. The surveyor's second report — preserved in the Annex of Unresolved Measurements, folio 719-Γ/9 — attributes the drift to the depression's western lip being 4 mm lower than its eastern lip, a geometry later found to match the habitual stance of Senior Archivist Aethelred, whose weight was carried, by long custom, slightly forward and to the left. Aethelred was at that time four years into a posting to the Aisle and had not, by his own account, noticed the floor changing beneath him. His statement to the survey is three words long and is quoted in full in the Annex: "It seemed softer."

Relation to the Aethelred Impression

The Stone's adoption as the baseline for the Aethelred Impression followed the Fourth Recension of the Survey Ordinances, which required that every standard of measurement in the Tower be traceable to a physical original rather than to a description of one. The drafters had hoped for a weight, a rod, or a sealed vessel. What the Librarians possessed was a dent.

The Pragmatists of the Leaning Stack objected at the time and have objected at intervals since, on the ground that a standard derived from a single archivist's posture cannot be reproduced by anyone who did not share that posture. The objection is recorded, answered, and still standing: the Impression is reproducible to within 0.2 cm by any clerk who leans forward-left with the heel of the left hand resting on the shelf edge, and the Fifth Concordance permits this approximation in all matters below the rank of structural certification. Above that rank, comparison must be made against the Stone itself, in person.

The 6.0 cm question

The nominal depth of 6.0 cm, set by the Eleventh Concordance, Annex 7, has never matched direct measurement. Field surveyors returned 6.2 cm in the year recorded as 4,140; 6.3 cm in 4,187; and 6.2 cm again in 4,201, suggesting that the Stone reached its present depth within a century and a half of Aethelred's departure and has since been stable. The Bureau of Standards, however, maintains that the Stone continues to deepen at a rate of one part in nine thousand per annum, and that the 6.0 cm figure is therefore correct, being the depth the Stone would have stood at had measurement been taken at the proper moment, which it was not.

"That a standard shall not agree with its original is no defect in the standard. It is the distance between the Tower as it is and the Tower as the Concordance would have it, and we are not required to close it."

— Eleventh Concordance, Annex 7, commentary

The Office of the Standard Impression holds the contrary view and has twice petitioned to have the nominal figure amended to 6.2 cm. Both petitions were ruled out of order: the first because it was filed by a clerk who had not personally visited the Stone, and the second because it was filed by a clerk who had.

Access and handling

Floor 719-Γ is reached by the service stair from the 719 landing and is open to holders of a reading ticket during ordinary hours. Visitors are asked not to stand in the Stone. The prohibition dates from the year recorded as 4,033, when an inspector from the Verification Corps stood in it for upwards of forty minutes while he read, added an estimated 9 mm to the measured depth, and thereby caused a recalibration of every Impression instrument in the Tower. The inspector's name is struck from the record; his error is not.

Dust is swept from the depression at the turn of each month and returned to the aisle from which it was drawn, in accordance with Ninth Concordance, Annex 2, which permits no dust to be reclassified. Two of the original surveyor's chalk marks remain visible on the northern lip and may not be wiped.

Dispute with the Pillar precedent

The Stone is frequently cited alongside The Leaning Pillar of Aisle Gamma-7 in matters of architectural deformation, though the two are not of a kind. The Pillar, which deviates 4.7 degrees from true vertical — a figure certified in the ruling In re: The Leaning Pillar of Aisle Gamma-7 — is a load-bearing member in a state of recorded disrepair. The Stone bears no load and is in no state of disrepair. It is, as the ruling in In re: Aethelred's Leaning Stone put it, "a use and not a fault."

That ruling also established that the Stone cannot be cited as evidence of wear in any adjacent aisle, and that the Condition of Recorded Disrepair does not attach to it. The distinction has not prevented the Pillar's advocates from citing the Stone's 6.2 cm measurement as proof that deformation progresses by degrees measurable in inches, a use of the figure that the Bureau of Standards has formally deprecated and cannot prevent.

Notes on the neighbouring record

The Stone should not be confused with Aethelred's Silence, the non-luminous stone accepted by the Registry as contextually unique, nor with the Aethelred Spiral, whose material audit was conducted by Foreman Aethelred — a different Aethelred, to whom the Stone has no relation and who has applied in writing to say so. The application is held, unanswered, in the Annex of Unresolved Measurements.

For calibration of common objects, the Aethelred Tome-Weight is preferred. For calibration of persons, see the Stone. It is the only standard in the Tower that must be stood in by someone who has read about standing in it.