Heat oven to
300F (150C). Grease and flour a loaf pan, 9 x 5 x 3-inch. Cream butter
or margarine until fluffy. Add sugar gradually and beat well after each
addition. Continue beating until mixture is fluffy. Add eggs, one at a
time, beating well after each addition. Stir in lemon rind and lemon
juice. Sift flour, baking powder and salt together and stir into first
mixture, stirring only until blended. Spoon into prepared pan and bake
about 75 minutes or until a toothpick stuck in the centre of the cake
comes out clean. Turn out and cool on rack.