Heat oven to 300 degrees. Grease and flour 10 inch tube pan. Cream shortening until smooth. Gradually add sugar and cream well. Add the eggs one at a time, creaming well after each one. Stir in lemon juice and vanilla. Sift cake flour and add to the mixture. Pour mixture into tube pan. Bake for 1 1/2 hours or until tests done. Makes 1 large cake (20 slices). Omit lemon juice and add 1/4 teaspoon freshly grated nutmeg with sifted flour.