Wash twelve small beets, cook in boiling water until soft, remove skins, and cut beets in thin slices, small cubes, or fancy shapes, using French vegetable cutter. Mix one-half cup sugar and one-half tablespoon corn-starch. Add one-half cup vinegar and let boil five minutes. Pour over beets, and let stand on back of range one-half hour. Just before serving add two tablespoons butter.