Phosphor Lanterns

Definition and construction

Phosphor Lanterns are standardized hand-carried illuminants issued to Tower personnel for passage in unlit corridors, stairwells, and inter-floor apertures. A Phosphor Lantern consists of a brass or copper-alloy housing, a borosilicate chimney, and a reservoir charged with a suspension of Creeping Phosphor-Moss spores in clarified tallow. The assembly produces a steady teal glow with a peak wavelength of 498 nm, consistent with the emissive profile recorded for the source cultivar.

Issue of Phosphor Lanterns falls under the Specifications for Vigil-Issue Illuminants and has been administered since the sealing of the Third Concordance by the Office of Lys, which retains a standing allocation of 4,000 units per Tower-year. Lanterns are numbered sequentially by housing stamp; the numbering series has been reset four times, most recently following the Fire of Uncatalogued Wicks on Floor 62.

Relation to source material

The luminescent charge in each lantern is drawn from harvested Creeping Phosphor-Moss, the photoluminescent cultivar already catalogued as a Luminous Symbiote of the Silent College scribes. Moss is gathered under Phosphor Scraping authority and rendered by the Office of Catalogic Logistics before delivery to the lantern-wrights. A fixed proportion of raw moss is diverted to the Biocompatibility Modulator under separate allocation, which accounts for its dull luminescence after the ninth hour.

Because the source material continues to translocate at an average rate of 2.4 centimeters per Tower-day even in suspension, sealed lanterns are required to be vented and recharged at intervals of no more than 40 days. Unvented lanterns accumulate spore residue against the chimney, producing a mottled rather than steady glow, and are rejected at inspection.

Standing prohibitions

Personnel issued a Phosphor Lantern are forbidden from carrying it across a threshold marked under Annex 7 of the Third Concordance. This prohibition, added by amendment in the Ninth Concordance, is enforced at aperture checkpoints and applies equally to extinguished units. Carriers attempting to argue that an extinguished lantern carries no light have been consistently referred to the amendment's preamble, which does not distinguish between lit and unlit states.

"A lantern is an instrument of passage whether or not it is presently burning, in the same manner that a key is an instrument of entry whether or not it is presently turned."

— Eleventh Concordance, Annex 3

A second prohibition, older and less cited, bars the refilling of any lantern with Lys-grade illuminant. Breach of this rule was the subject of Dispute Resolution Protocol 12-C, filed on behalf of the wardens of Floor 714 following the Phosphor Scraping incident.

Disputed classifications

The Practicalist School maintains that a Phosphor Lantern is a container rather than a light source, and that its glow is an incidental property of containment. Under this reading, lanterns are properly inventoried alongside sealed jars and stoppered flasks, and their charge levels are a matter for the moss-harvest schedule rather than the illuminants register. The Librarians have never formally ruled on the distinction; the two offices continue to file conflicting returns each quarter.

A rival account, associated with Selena Moss and referenced in discussions of Luminal Moss, holds that the lantern's brass housing is load-bearing in the conceptual sense, and that removing the charge from a numbered housing without reissuing the number produces a lantern-shaped absence that will nonetheless be counted at the next inventory. This claim is not corroborated by the inventory records of Floor 62, though the records for that floor are known to be incomplete.

Maintenance notes

Lantern chimneys are cleaned with a dry cloth only; the use of solvent will dull the teal cast and render the unit non-conforming to Specifications for Vigil-Issue Illuminants. Personnel are reminded that lanterns issued for a specific spiral designation, including the Gamma Spiral Designation and the Lys-Gamma Spiral, are not transferable between spirals even where the aperture markings appear identical. Lanterns found unattended in a corridor are collected by the Office of Lys and held for 90 days before reissue; they are not returned to the original bearer.

See also

• Specifications for Vigil-Issue Illuminants
• Creeping Phosphor-Moss
• Phosphor Scraping
• Annex 7 of the Third Concordance
• Key of Absent Resonance
• Breath-Score Fragments