Sometimes he imagined the building as an iceberg whose visible tip included the main floors and eaves and whose submerged mass began below the first level of cellars: stairs with resounding steps going down in spirals; long tiled corridors, their luminous globes encased in wire netting, their iron doors stencilled with warnings and skulls; goods lifts with riveted walls; air vents equipped with huge, motionless fans; metal-lined canvas fire hoses as thick as tree trunks, connected to yellow stopcocks a yard in diameter; cylindrical wells drilled into solid rock; concrete tunnels capped with regularly spaced skylights of frosted glass; recesses; storerooms; bunkers; strongrooms with armour-plated doors.