Cream 1 cup of sugar and 1 cup of softened butter. Add 1 egg and 2 teaspoons of vanilla. Blend 2 cups of flour, 1/2 teaspoon baking soda and 1/2 teaspoon cream of tartar. Refrigerate for at least 1 hour. Drop on ungreased cookie sheet by rounded measuring tablespoon. Bake at 375 degrees for 8 to 10 minutes.