The chamber of the Great Planisphere occupied the uppermost apex of the Grand Scroll hall, carved into the solid granite ceiling sixty arm-lengths above the library terraces.
To reach this sky safe hall, Qiao Ming and Yan Zhiqiu climbed a spiral stairs of white pale limestone comprising two hundred and forty-eight steps. Each step had been cut with a curved bullnose to conduct moisture downward, leaving the central tread dry and level beneath their bare calloused soles.
The ascent through the upright shaft was a sound journey through the mountain’s breathing layers. At the twentieth step, the gentle lap of the harbor basin was still heard. At the eightieth step, the sound died into the hollow drone of the upright air-flow drain tubes. And by the two-hundredth step, all external noise had vanished, replaced by the deep, ringing silence of the high bedrock.
As they crossed the threshold of the upper portal, they entered a hemispherical tiered arena seventy arm-lengths in width. The dome above was not made of timber or brick, but was a flawless inverted bowl of black dark rock, polished to the shiny bright glare of black glass.
The hemispherical chamber had been carved from a single dome of crystal-clear red stone, an igneous rock so dense that neither ground-shaking shock nor underground water-slow leak could penetrate its matrix. The First Patriarchs had lined the inner ceiling with three thousand slabs of polished black dark rock, each cut into an irregular pentagon and fitted together using tongue-and-groove…
