One by one the visitors started to come back to the Ark, to walk around the gardens and admire the blossoms on the trees and the bobbing heads of the daffodils. Dr Thomas Wharton, a man after John’s heart, came to look at the rarities and brought with him a proposal that John should set aside a part of his garden for the College of Physicians. They would pay him a fee to grow herbs and medicinal plants for them.

‘I appreciate it,’ John said frankly. ‘These have been lean years for us. A country at war has no interest in gardening nor in rarities.’

‘The country is to be run now by men whose curiosity will not be stifled,’ the doctor replied. ‘Mr Cromwell himself is a man who likes ingenious mechanisms. He has drained his farmland and uses Dutch windpumps to keep the water out, and he believes that English land could be made to yield as fruitfully as the Low Countries’, even the waste grounds.’

‘It’s a question of not exhausting the soil,’ John said eagerly. ‘And changing the crops around so that blights don’t take hold. We’ve always known that in gardens and vegetable plots, every convent and monastery garden moved crops from one bed to another each year; but it’s true for farmland too. It’s how to restore the goodness to the soil that is the difficulty. In Virginia too, the People never use the same field for more than three seasons.’

‘The planters?’

‘No, the Powhatan. They move their fields each season. I thought it was a mistake till I saw how their crops yielded.’

‘This is most interesting,’ Dr Wharton said. ‘Perhaps you would come to my house and tell me more. I meet with friends once a month to discuss inventions, and rarities, and ideas.’

‘I should be honoured,’ John said.

‘And what d’you use to make your own land fertile?’ Dr Wharton asked.

John laughed. ‘A soup of my father’s devising,’ he said. ‘Nettles and comfrey and dung stirred up in an evil pot. And if I am disposed to make water I piss in it as well.’

The doctor chuckled. ‘So it couldn’t be used for a hundred acres?’

‘But there are crops which would put the goodness back into the soil,’ John replied. ‘Comfrey or clover. You’d have to start with a little patch and harvest the seed, plant a greater and greater field every year.’