1. Blend sugar, corn syrup, water, and butter. Cook to 230'F. on a candy thermometer. Add peanuts and cook to 280'F. Stir occasionally and continue cooking to 305'F. Remove from heat. 2. Add baking soda and stir quickly until mixture foams. Quickly pour into 2 buttered 15x10x1" pans and spread thinly over entire surface of pans. Cool until hard and break into pieces.