Fools' Gold by Philippa Gregory Page B

see,’ Ishraq exclaimed, suddenly understanding. ‘I have a gold ring, that I know is pure gold.’
    ‘It’s hollow, it’s in the shape of a ring,’ Luca said, thinking furiously aloud. ‘Doesn’t matter. The central hole has no weight. We are weighing the gold of the ring not measuring the area. Get it.’
    ‘It’s Isolde’s mother’s ring,’ Ishraq explained. ‘I have carried it and her family jewels for her ever since we left home.’
    ‘Are you sure it is pure gold?’
    She nodded. ‘The Lord of Lucretili would have given his lady nothing less,’ she said.
    He did not even hear her, he was looking from the gold nobles to the water in the glass. Ishraq ran from the room up the stairs to the girls’ rooms and lifted her gown, to rip at the hem of her linen shift.
    ‘What on earth are you doing?’ Isolde asked. She was standing on a wooden chair, a dressmaker kneeling before her, hemming a gown. On one side a tirewoman was making a magnificent headdress and there were carnival masks all around the room, silks, satins and velvets thrown everywhere in a jumble of richness and colour.
    ‘Getting your mother’s gold ring,’ Ishraq said tersely, tearing at the delicate hem stitches. ‘For Luca to weigh against the gold nobles.’
    ‘Still?’ Isolde said irritably. ‘You’ve been locked in all morning. And I heard you drop a plate.’
    ‘Smashed it,’ Ishraq said cheerfully, retrieving the ring and pulling down her dress again.
    ‘Make sure he doesn’t damage it,’ Isolde said disagreeably. ‘That ring is valuable.’
    Ishraq said nothing but raced back to Luca. He was pacing up and down, scowling in thought, he hardly noticed her come in until she put the ring into his hand.
    At once he turned and put it on the delicate spice scales that Freize had brought them from the kitchen. He added the tiny weights – the smallest was half a grain of wheat. Isolde’s mother’s ring was just over 121 grains.
    ‘Write it down,’ Luca ordered Ishraq. ‘The ring is pure gold, 121 and a half grains. Now. How much water does it move?’
    Luca lifted it from the scale and put it into the water glass. At once the water rose within the glass. With a sharp piece of chalk Luca marked where the water level rose, and then hooked the ring out with a fork and held it over the water so that every drop fell back into the glass and the water level was the same as before.
    ‘You are certain this is pure gold?’ he asked quietly.
    Ishraq was impressed with his concentration. ‘Certain,’ she whispered.
    ‘Well, the noble should be 108 grains,’ Luca said. ‘And the noble plus half of one of the quarter nobles should be exactly 121 and a half grains. So the mass is the same. If it is less dense, then it has been mixed with tin or something lighter than gold, and the water will rise higher.’ Gently, without making a splash, he dropped the full coin into the glass of water, and then dropped the sawn half of the quarter noble on top of it.
    They both held their breath as the water level rose, sticking to the side of the glass, but definitely rising up and up until it reached the mark set by the ring.
    ‘The coins are pure gold,’ Luca said in quiet triumph. ‘Someone, somewhere is either stealing English nobles fresh from the mint in Calais, or else they are mining the purest gold, and forging their own.’

    The five of them were elated, as if they had found the gold mine itself.
    ‘So what next?’ Isolde asked. ‘How will we find the mint? How will we find the forgers?’
    ‘Could we buy so much gold that the money changer cannot serve us from his own store?’ Luca suggested. ‘Then we’ll ask him where we can go to collect it. If he won’t say, we’ll have to watch him, see where he goes to get a chest of gold.’
    ‘We can take it in turns to watch . . .’ Ishraq started.
    Luca shook his head. ‘No, not you,’ he said. He glanced at Isolde and saw her nod in agreement. ‘I am sorry, Ishraq, but