Sift together the flour and baking powder three times. Add the lemon rind and nutmeg to the butter and work with a spoon until fluffy and creamy. Gradually add 1 3/4 cups of the sugar while continuing to beat with a spoon until light. Beat egg yolks with hand or electric mixer until light colored and thick enough to fall from the beater in a heavy, continuous stream. Add to butter mixture and beat thoroughly with a spoon. Beat egg whites with a hand or electric mixer until stiff enough to stand up in peaks, but not dry. Add remaining 1/2 cup of sugar, 2 Tbs at a time, beating after each addition until sugar is *just* blended. Stir 1/3 of the flour mixture into the butter mixture, then 1/2 of the egg whites, repeating until all is used, beating very thoroughly with a spoon after each addition. Turn into two 10" x 5" x 3" loaf pans which have been greased, paper lined, and greased again. Bake in a moderate oven of 325 degrees for 1 hour and 20 minutes, or until done. This recipe is from the 1942 Good Housekeeping Cook Book.