‘What you’re asking from me is more than I can reasonably give you,’ Laurence Melford told Collis. ‘My whole livelihood depends on keeping Northern California isolated from the East; and apart from that, I am a Southerner, and I know what a transcontinental railroad route will do to the South’s economy.

‘But I will make a bargain with you, Edmonds. You’re looking for investment in your railroad. Well, I’ll make that investment myself, up to fifty-thousand dollars, but on the strict condition that it’s kept a secret. And on the condition that I don’t have to write any letters of support to the newspapers.’

Collis sat back in his chair. ‘Fifty-thousand dollars? In negotiable bonds? Or what?’

‘Fifty-thousand dollars in gold. Payable over six months.’

‘That sounds fair. But if you can’t bring yourself to support the railroad in public, why give me money in private?’

‘Because I happen to know how much railroads cost,’ said Laurence Melford. ‘I happen to know the price of rail, the price of locomotives, the price of timber, and the price of labour. Fifty thousand dollars, if you’re lucky, might buy you one trestle over one river. It won’t be anything more than a drop in an ocean, and if you’ll return those calotypes for that amount, then you’re welcome to it.

‘What I will not do, ever,’ he continued, ‘is endorse your railroad to my friends. For if I do so, I will be publicly denying my most deeply held principles. I will be publicly denying the South, and I will be publicly denying my belief in Northern California as a haven from the machinations of North-eastern industrialists. Even my daughter’s reputation is not worth that much.’

Collis got to his feet. Carlo, the maître d’, was just arriving with his second drink, but when he saw Collis’s face, he stood a little way off and waited, chewing his lip. Collis looked at Laurence Melford for a moment or two, and then he buttoned up his gloves.

‘I admire your integrity, Mr Melford,’ he said. ‘I only wish I could admire those prejudiced and self-serving interests which you so mistakenly believe are “principles” — the subjugation of the Negro against all humanitarian credenda, and the deliberate isolation of a whole people from the benefits of modern progress for the sake of two or three profiteering monopolies.’

Laurence Melford’s self-control almost broke. He held up his fork in his white-clenched fist, and he bent it as if it were made of the cheapest zinc, instead of steel. The maître d’ turned away, and with one deft tilt of his head, drank Collis’s second stone fence himself.

‘Mr Melford,’ Collis said, ‘you can make up the fifty-thousand dollars in five ten-thousand-dollar sacks, and have them delivered once a month by messenger to myself at 54 K Street, Sacramento. Do you know how many calotypes there are?’

‘The letter said ten,’ said Laurence Melford tightly.