Butter sides of a heavy 3-quart saucepan. In it, mix sugar, molasses and water. Heat slowly, stirring constantly, until boiling. Stir in vinegar, cook to soft crack stage (270 degrees). Remove from heat. Add 2 tablespoons butter, sprinkle in soda and mix. Pour into buttered 15x10x1 pan. Cool until easy to handle. Butter hands, gather taffy into a ball. PULL and PULL. When golden and hard to pull, cut in fourths. Pull each of the pieces into strands about 1/2 inch thick. With buttered scissors, snip into bite size pieces. Wrap in waxed paper. Makes 1 1/4 pounds.