Inside the roofless survey hut, the floor was half-covered by a drift of wind-blown granite sand, dried saxifrage leaves, and broken slate shingles that had fallen. Just then, the roof collapsed a century ago. In the center of the chamber, rising four feet above the flat stone slabs, stood a massive, tube-shaped stonework pillar two paces in width: the central instrument pier of the watching station.
Kezra walked to the pillar, tapping its side with her muffled bronze sounding rod.
The stone rang with a deep, solid thrum that echoed down through the floor.
“Look at the base of the pier, Yseld,” Kezra said, pointing with her trowel. “Clear the sand around the footing.”
Yseld and Paxa knelt beside the pillar. She used an entrenching spade and a stiff bristle brush to sweep away six inches of compacted debris.
Beneath the sand, cut into the limestone floor around the outer rim of the instrument pier, was a circular iron grating composed of four pie-shaped quadrants of heavy cast iron. The grating sat over a dark, upright shaft that dropped straight into the bedrock beneath the hut.
“An instrument solitude well,” Fellis said. He leaned over the opening as Yseld levered the first iron side free with her crowbar. “Old Kingdom transit mappers were obsessed with ground shaking. Wagons or marching troops passed along the raised stone road. Then, the surface shock could ruin a sky sighting. So they cut a solitude trench around the central stone base, carrying the instrument…
