Grey

Grey is the collective designation for the class of monotonal substances, lights, pigments, and imprints administered under the standing authority of the Grey Convocation, and recognized throughout the Tower as the only properly neutral tonal register. Grey is not a colour in the ordinary sense but a category of materials whose defining property is the suppression of preference: a grey substance, correctly prepared, makes no claim on the eye and therefore makes no claim on the record. By the definitions set out in Annex 12-C, anything that can be shown to have been neither warm nor cool in its original state may be entered as grey, provided the entry is attested by two Librarians and countersigned in the register of the floor where the substance was found.

The class contains, at minimum, the following certified materials, each of which has its own separate holding and should not be confused with the class as a whole:

• Cartographic Grey — the perpetual, uniform light-source used in the Convocation's chamber to nullify chromatographic bias.
• Wax Cylinder Standard Issue Grey — the recording medium of the Convocation's auditory registers.
• Indelible Grey — the ink of the Grey Ledgers, permanent yet perpetually unfinalized.
• Grey 7 — a dull grey ink reserved for the application of Imprint 712-Omega.

Origin and the Question of the Ground Tone

The Tower's grey does not appear to have been manufactured. The earliest surviving inventory of the Grey Stacks, compiled some four centuries before the Grey Niche debates, lists "grey, indeterminate quantity, in the lower coffers" without further specification, and no subsequent recension has been able to trace a supplier. The Intercalary School maintains that grey is a naturally occurring deposit, laid down in bands and quarried much as any other mineral; the Grey Convocation has never confirmed this, and its own position — that grey is found rather than made, and that the distinction is not one the Convocation is required to settle — is reproduced verbatim in every edition of the Convocation's standing preamble.

The alternative account, advanced in the Grey Basin Transcripts and never formally withdrawn, holds that all grey is a residue: that the Tower's surfaces were once variously coloured and that grey is what remains when the colour has been read off them by long use. This is the position of the so-called depletionists, who point out that the deepest galleries carry the most uniform grey and the most heavily consulted floors the least. The Convocation has declined to rule on the matter, noting in a footnote to Annex 12-C that the question "pertains to origins and not to entries, and entries are what the Convocation is for."

The Niche Dispute

The most sustained disagreement in the grey literature concerns the Grey Niche and its custodian, Alban Kells. The Grey Niche debates of that period turned on whether a deposited grey substance acquires the neutrality of its surroundings or retains the neutrality of its original state. Kells held the former view and, by way of demonstration, permitted a sample of Grey 7 to remain in the Niche for the full intercalary term; at the term's close the sample had not altered in tone by any measurement then available, a result Kells interpreted as proof of acquired neutrality and his opponents as proof that the sample had never been neutral to begin with. The disputation was never resolved and was eventually closed by the simple expedient of sealing the Niche. Kells's custodianship is recorded as concluded in the same year, though the register does not say by what instrument.

"A grey that changes is not grey; a grey that does not change is not a demonstration. The Niche is therefore closed."

— Grey Niche debates, closing minute, appended without signature

Conflict of Concordances

Grey is governed by two instruments that do not agree. Annex 12-C provides that grey materials may be entered in the Grey Ledgers without tonal attestation, on the reasoning that a grey substance cannot misrepresent itself. The Fourth Concordance, Annex 2, provides the opposite: that no substance may be entered without attestation, grey being "the register most easily imitated and therefore the register most in need of witnesses." Both annexes remain in force. The practical result, documented in the Grey Expedition Affair, is that entries made near Floor 940 are routinely attested by clerks who then record the attestation as unnecessary, producing a double entry that must later be reconciled by the Intercalary School. The School has petitioned for a ruling eleven times; the Convocation has replied eleven times that the matter is one of Concordance and therefore not within its remit.

Later Development

The methods of Hieronimus of the Grey Stacks transformed the treatment of grey in the upper floors. Hieronimus demonstrated that grey could be numbered — assigned a position in a numeral sequence rather than described in words — and that numbered grey could be compared across floors without the intervention of a witness. His demonstrations, conducted in the Grey Stacks and recorded in the Grey Basin Transcripts, established the practice of Numerative cataloguing that the Echo Recovery office now applies to abandoned sound records. The demonstration did not resolve the depletionist question, and Hieronimus is not recorded as having attempted to.

Grey remains, in the Convocation's own phrasing, "the register in which the Tower's disagreements are kept legible." Practically, this means that a reader consulting a grey holding should expect to find the holding itself unambiguous and every account of it disputed. The Convocation's maintenance notice for the chamber is posted at the door and reads, in full: the light is not to be adjusted. It is not adjusted.