Peel the pears and put them in a bowl of cold water acidulated with the juice of the lemon. Cut the pears into slices and return sliced pears to acidulated water. In a small saucepan combine the red wine, the Port, the cinnamon stick, the cloves, and the rind, bring the liquid to a boil, and boil the mixture for 5 minutes. Add the sugar and simmer the syrup, stirring, until the sugar is dissolved. Add the pear slices, drained, and simmer them for 5 to 7 minutes, or until they are tender. Let the pear slices cool completely in the syrup. The pear slices may be prepared up to this point 1 day in advance and kept covered and chilled in the syrup. Divide the pear slices among 4 bowls and spoon some of the syrup over each serving.