Cream 1 cup sugar and 1 cup butter. Add 2 eggs and 1 teaspoon vanilla. Beat well. Sift together 4 cups flour, 1/2 teaspoon cream of tartar or baking powder and 1/4 teaspoon salt. Stir in cream mixture. Add 1 teaspoon baking soda dissolved in 2 tablespoons buttermilk. Mix thoroughly. Turn out on lightly floured board and roll to about 1/4 inch in thickness. Cut with large round cookie cutter and bake in moderate oven 12-15 minutes.