Once the boy had passed his baccalaureate, he had done his best to initiate him into the delights of public construction – there was no memory of any de Rigny having ever done anything else, at least since Colbert – but so vacant were Auguste’s eyes on the occasion of his last site visit that Casimir had sadly concluded the boy was not at all suited to such matters. This was in stark contrast to his other son. Ferdinand, having adopted and made his own the extraordinary legal construct that was the public limited company – namely an ability to conduct business without any liability for its failures – had managed the remarkable feat of quadrupling his assets by the age of twenty-seven, while taking like a duck to the troubled waters of awarding public contracts.

‘What’s to become of this boy and his unhealthy sensitivity?’ Casimir would often wonder if he happened to be pondering his son Auguste. ‘He seems incapable of imagining doing anything with himself.’

He saw only one explanation for the significant difference between his two children: whereas the eldest, Ferdinand, had developed both in strength and energy, the youngest had succumbed in quick succession to every conceivable illness from the day he was born – and, like every child wrestled from death, he had been far too spoiled by his mother.

Physically he belonged to that species of tall, thin types with a broad forehead and dead-straight blond locks that he flicked off his face. His large dark eyes shone like horse chestnuts, lending him a fanatical air, as if ravaged from within, with a slightly effeminate touch. He considered himself a philosopher or poet, or both, coming out with particularly infuriating inanities such as: ‘I’d love to learn a manual trade so I might help my fellow man, brother to brother.’ He would go around predicting that he would die at thirty-three, like Christ, which women found highly entertaining. His parents, much less so.

After turning family mealtimes into a great headache by declaring suddenly one day that he was adopting a Pythagorean diet, a regime spurning all animal flesh, his latest infatuation was socialism, or more precisely the writings of a philosopher – a certain Marx – who was living in exile in England, about whom he would harp on endlessly at every opportunity. This most recent fad had disrupted the household’s peace and quiet once and for all, with the two brothers constantly bickering, each time further testing the limits of acceptability. It had reached the point where Casimir had had to beg his sister Clothilde, who lived in Paris, to take Auguste in so as to remove him from Saint-Germain until he had had a chance to mature.

Clothilde herself was not without her failings.