Peel pears, leaving stems intact. Place them in a large, nonaluminum pot with enough water to cover. Add sugar, spices and lemon juice. Cover pears with a round of wax paper cut to fit interior of pot. Bring to a boil, reduce to simmer and cook until pears can be easily pierced with a knife. Slice away skin and pith from oranges. Remove pears to a serving bowl and add enough syrup to cover. Place oranges in cooking liquid and simmer for 15 minutes or until tender. Peel and seed melon. Cut into long, 3 cm wide strips. Add melon strips to the poaching oranges and simmer for 5 minutes. Remove to serving bowl. Add grapes and lemon slices to poaching liquid and simmer for 3 minutes. Remove to bowl. Add curry powder to liquid and whisk to dissolve. Cook syrup until reduced by half. Strain through a double thickness of dampened cheesecloth. Drain away any juices that have collected in serving bowl and pour syrup over fruits. Serve fruit with a little of the crystallized ginger sprinkled over each portion.