Annex to Memorandum Delta12 Ge to Gtm

The Annex to Memorandum Delta12 Ge to Gtm (catalogued GTM/GE-Δ-A1, sometimes cited simply as the Annex) is the appended schedule of measurements, specimen registers, and procedural riders filed with Memorandum Delta12 Ge to Gtm on 14 Serein, 412. Where the parent memorandum set out the seventeen points of procedural divergence from GTM Ordinance Δ-117 in argument, the Annex set them out in figures, and it is the figures that have been litigated ever since. The Annex is the earliest surviving document to fix a numerical tolerance for the measurement of stairwells, and it is the proximate cause of the Reckoning of Stairs as a standing office rather than an occasional survey.

Composition and recensions

The Annex was issued in four schedules. Schedule I reproduces the columnar tables of the parent memorandum without alteration. Schedule II establishes the Caliper Masters rank, a provision carried in the body of the parent document but given its measurable standard here: a Caliper Master is one who has taken the Annex's reference bar three times in a single winter without variation exceeding one part in nine thousand. Schedule III is the specimen register. Schedule IV, the longest, is a list of things the Annex does not undertake to measure, and it is Schedule IV that has been recopied most often.

Three recensions circulate. The first, held in the Delta stacks, carries the seal of the Guild of Exactitude and is regarded as authoritative. The second, a GTM copy filed with the Concordance Web, omits the marginal notes of the clerk Ovin Marrow and so misnumbers two Schedule II entries. The third survives only as an excerpt in the White Memorandum on Temporary Entities and is, in the words of its own colophon, "not to be measured against, only read."

"Let no bar be struck in a heated room, nor in a room where a lamp of the Ge class is burning; for the bar will answer to both."

— Annex to Memorandum Delta12 Ge to Gtm, Schedule II, rider 6

The stairwell tolerances

Schedule I is remembered almost entirely for a single line, which sets the permitted variation in riser height across a surveyed run at one part in two hundred and forty, with a carrying allowance of four additional parts where the run exceeds nineteen steps. The figure has been blamed for nearly everything that followed. Concordance XII, Annex 2, retains it unaltered; Concordance XIX, by contrast, declares in its preamble that "the two-hundred-forty tolerance was framed for a stair that does not turn" and proposes a flat one part in one hundred for all spiral work. No recension of the Annex has ever been withdrawn, and both figures remain in force on different floors.

The disagreement is not merely numerical. A body of opinion, associated with the surveyor Heseline Voth, holds that Schedule I was never intended as a tolerance at all but as a worked example, and that its elevation to standard was an error of the scribes. Voth's argument rests on the Annex's own arithmetic, which she demonstrates to be internally inconsistent by a margin of three. The Caliper Masters have declined to rule on the question, noting only that the Annex has been measured against for three centuries and that a standard which has been used is a standard.

Specimen register (Schedule III)

Schedule III was compiled to demonstrate that the divergence provisions could be applied to objects as readily as to procedures. Its inventory is short and has been reproduced entire in every recension.

• One reference bar, brass, unmarked, of indeterminate length (the length is given as "the bar itself").
• Two lamp mantles of the proposed class, unlit, one of which was subsequently mislaid.
• One set of fantastical geometry samples, load-tested to destruction, entered jointly with the Quarrymens Guild.
• Four stair treads, removed from a stairwell on a floor the register declines to number.
• One sealed envelope, contents not entered, endorsed "for the Reckoning".

The envelope is the subject of an unresolved request from GTM/GE-Δ for its opening, opposed on the ground that the Annex nowhere empowers its own unsealing. The mantles were the subject of the Inertial Dampeners Complaint, which the parent memorandum superseded; the Annex's entry for them was nevertheless never struck.

Schedule IV and the question of scope

Schedule IV has attracted more commentary than the rest of the Annex combined, largely because of what it excludes. It declines to measure drafts, echoes, the interval between a bell and its sounding in a stairwell, and the number of steps a visitor believes they have climbed. The Guild of Theoretical Mechanics (GTM) has argued that the last exclusion establishes a general principle — that belief is outside the Annex's competence — and has cited it in the GTM White Paper on Phenomenological Inertia. The Guild of Exactitude replies that Schedule IV is a list of omissions and not a doctrine, and that to read a principle into an omission is precisely the vice the Annex was drafted to prevent.

Rider 11 of Schedule IV is the most frequently quoted line in the document and the least often obeyed: "Where a measurement cannot be repeated, it is to be entered once and marked provisional." The Memorandum Delta3 Gtm to Ge objected that provisional entries had multiplied beyond any hope of pruning, and the parent memorandum had already recommended their eventual reduction. No pruning has occurred. The provisional entries now fill eleven volumes, and the clerk Ovin Marrow, whose marginal notes occasioned the second recension, is recorded as having requested a twelfth and been refused on the ground that the Annex provides for eleven.