4 ideas
Robert-François Damiens wounded Louis XV with a penknife and was executed on the Place de Grève in Paris. His hand was burned, his flesh torn with pincers, and molten lead and boiling oil poured into the wounds. The novel treats the carefully planned procedure and the paying audience as the real evidence, more than the condemned man himself.
The worst atrocities in European history were carried out by courts, clergy, officials and executioners following rules, not by outlaws. Legal form such as sentences, protocols and prescribed methods of killing turns a torturer's sadism into a civil servant's obligation, so no one involved feels like a criminal. The more rational and documented the system, the more cruelty it can sustain without anyone feeling guilt.
Read any public punishment by looking at the audience instead of the victim or the executioner. The crowd's appetite, the paid seats and the festive atmosphere show that cruelty is a shared pleasure of ordinary people, not a pathology of a few. The narrator's own compulsive cataloguing, and the reader's reading, are placed inside that same audience.
The 'powderhouse' is a picture of civilized society as a store of hidden, accumulated violence that looks calm and orderly from outside. Refinement and progress do not remove this destructive potential; they pack it tighter until it detonates, as in the wars and camps of the twentieth century. Apparent peace is therefore a sign of stored charge, not of safety.