Aperture Sigma Press

The Aperture Sigma Press is a fixed-body mechanical press of the vertical-screw class, housed in the north bay of Aperture Sigma on Spiral 44. It is the Tower's principal Conceptual Press, employed in the pre-cataloguing of potentialities — that is, in rendering subjects not yet admitted to the archive into a form the archive can hold. It is not a printing press, though it is frequently mistaken for one by visiting parties from the lower reaches, and the bay staff no longer correct the error.

Its output is enumerated floor by floor at Aperture Sigma-7 and registered under the standing protocols of the Annual Register Sigma-14,022. The Press has operated, with interruptions, since Tower Year 209. Its dimensions are given in the survey of Year 388 as eleven cubits by four, exclusive of the screw, which projects through the ceiling of the bay and is not counted by anyone.

Construction and class

The Press belongs to the vertical-screw class described in the Register of Presses, Class II: a fixed platen above, a rising bed below, and a screw of laminated sigillic stock that advances by fractions of a finger-width per revolution. Unlike the larger Large-Scale Conceptual Press of the Central Press Hall, it does not require a full quorum of operators; two attendants and a reading clerk suffice for most grades of work.

The screw is turned by a walking-beam of Aperture Sigma-3 manufacture, counterweighted with spent floor-numbers. Bay practice holds that the counterweights must be replaced whenever the Press is reseated, and that a counterweight from a floor still in service must never be used. The reason is not recorded. The rule is nonetheless observed, and the Wardens of the North Bay inspect the weights quarterly.

Operation

Work at the Press proceeds in three movements: seating, impression, and recovery. A potentiality is first seated on the bed in a bound docket supplied by the Scriptorium of Provisional Forms; the screw is then advanced until the docket registers resistance at the gauge, conventionally between the fourth and sixth mark; the bed is finally lowered and the impressed sheet conveyed to Aperture Sigma-7 for enumeration.

Recovery is the longest movement and the least understood. An impressed sheet continues to settle for a period of between two days and nine years, and may not be enumerated until it has done so. The Standing Protocols of the Annual Register fix the settling period for ordinary classes at forty days, a figure the north bay has petitioned against four times without success.

"No potentiality shall be reckoned catalogued until it lies flat, and no sheet shall be reckoned flat until it has been weighed twice by different hands."

— Annual Register Sigma-14,022, Protocol 9

The Voight grievance

Between Years 4009 and 4013 the junior archivist Anselm Voight lodged a grievance concerning the Press, the substance of which was that potentialities seated in the north bay tended to return from enumeration bearing the marks of the bay rather than their own. Voight's memorandum of 12 Vesna, Year 4010, instanced a docket of unassigned stairwells that emerged impressed with the grain of the platen and could not thereafter be distinguished from the platen itself.

The grievance was heard by the Office of Impressed Subjects and dismissed in Year 4013 on the ground that a potentiality with no marks of its own has nothing to lose by acquiring the marks of the Press. Voight was reassigned to the Lower Inventory and his memorandum survives only in the recension appended to Concordance 4,411. The north bay still cites the dismissal as settled doctrine; the Office has never withdrawn it.

Disputed siting

The Third Concordance places the Press in the north bay of Aperture Sigma without qualification. The Sixth Concordance, Annex 2, places it in the south bay, and adds that the north bay was at the time occupied by the Halved Bell. The Concordance of Surveyors of Year 1,022 supports the north bay, noting that the Bell's containment took place later and elsewhere in the aperture.

The dispute is not merely antiquarian. Under the reinforcement protocols of Year 211 the mandatory symbolic bracing of the bay depends on which wall the Press is braced against; the northern bracing has been renewed eleven times, the southern never. Survey parties have twice attempted to settle the question by plumb-line and returned with measurements that disagreed between members of the same party.

Relationship to the Sigma apparatus

The Press is not itself a source of Sigma Pulses, but its impressions are used to calibrate them; the dissipation apparatus at Aperture Sigma-12 takes its baseline from the most recent settling sheet. Access to the north bay is by Stairwell Sigma-44, which connects to the Aperture Sigma-7 stairwell and serves the upper recorded reaches of Line Sigma.

Personnel entering the bay are asked to leave their own footwear at the threshold and to take a pair from the rack. The Press is not to be addressed by name.