Drain pears, reserving all liquid. Dice pears and add enough reserved pear liquid to make 1-1/2 cups total. Mix in egg and lemon peel; set aside. In medium bowl, cream butter and sugar until light and fluffy. Stir in flour, baking powder, ginger and salt; mix until crumbly. Stir in wet ingredients just until moistened. Stir in currants. Spoon batter into greased and floured 9x5-inch loaf pan. Bake at 350°F, 70 to 75 minutes, or until golden brown and toothpick inserted in center comes out clean. Remove from oven and cool before slicing.