Præsidium

First Appearance and Context

During an ascent to the Starhenge amid a passing storm, the tower’s interior stair is described; on descent into a stone cupola, the Master of the Keys stands by a portcullis, and the gridirons of adjacent towers are observed closed during Apert. Later accounts describe reaching an inward‑curving vault that spans the top of the Præsidium, with power shafts piercing the stone‑work to drive rooftop instruments, and a stair that spirals around the largest shaft to a controlled door opening onto the roof.

Roles/Actions and Affiliations

• Architectural and mechanical hub of the Mynster; it carries the great clock’s dials and anchors the rooftop instruments.
• Access to the upper works is controlled by tower portcullises that are scheduled at night by the Master of the Keys so that only one cohort has the stair at a time.
• Structural coupling: vertical shafts pass through the summit vault, delivering power between the tower and the roof’s driven polar mounts and other instruments.
• When directed by hierarchs, portcullises may be held closed even in daylight, temporarily sealing access to the roof.
• Windowed upperworks complement the inward watch associated with the Warden Regulant and the outward watch above; both overlook the Concent.

Relationships

• Integrated with the rooftop Starhenge and the larger fabric of the Mynster.
• Access patterns are administered by hierarchs (e.g., the Master of the Keys) in coordination with broader observance schedules.

Descriptions/Characteristics

• Central tower with high clock dials and an interior spiral stair that rises through tracery walls to the roof.
• Four corner towers with portcullises and a stone cupola at the stairheads; closures can be coordinated across towers.
• An inward‑curving stone vault spans the top of the tower; a stair spirals around a major power shaft to a controlled door leading onto the roof. The edge drop from the roof is sheer, with megaliths forming a ring near the perimeter.
• Rooftop structures include domes and a ring of standing stones set among the instruments.

Current Status/Location

Active at the heart of the Mynster. It continues to support timekeeping and observation from the rooftop. Portcullises are configured at night to regulate access; at times, multiple towers’ gridirons have been observed shut even in daylight, temporarily sealing the approach to the roof.