1. Sift flour, baking soda, salt and mace onto waxed paper.
2. Cream shortening with brown sugar until fluffy in a large bowl; beat in egg and milk. Add dry ingredients, blending well to make a thick batter; fold in rolled oats and walnuts.
3. Drop by teaspoonfuls, 3 inches apart, on greased cookie sheets
4. Bake in moderate oven (375°) 12 minutes, or until lightly golden. Remove from cookie sheets; cool completely on wire racks.