Combine cornmeal, baking soda, and salt; cut in shortening until mixture resembles coarse meal. Add buttermilk and milk, stirring just until dry ingredients are moistened. Form batter into eight 1/2 inch thick cakes. Place on a hot greased griddle. Bake at 400° F. for 15 minutes. Turn and bake an additional 15 minutes. Serve hot with butter.