Peel the pears, quarter them and take out the cores. Grate the rind off the lemons and squeeze out the juice. Layer the pears, sugar and lemon rind in a large bowl and sprinkle the lemon juice over the top. Cover the bowl and leave overnight. Transfer the pears to a large casserole, covering them with the juice which has formed during the night. Add cinnamon and cloves. Cover with a lid and bake at 275°F, 140°C, gas mark 1 for six hours until the pears are tender and golden. Leave to cool, and then stir in the brandy. Remove the cinnamon stick and cloves, and transfer the pears to jars, screwing them down for storage.