Line two cookie pans with parchment paper; set aside. In medium saucepan, combine sugar, corn syrup, water and salt. Cook over medium heat, stirring until sugar is dissolved. (Do not stir mixture once sugar has dissolved.) Use pastry brush dipped in water to wash sugar crystals down sides of saucepan. Secure Candy Thermometer on side of saucepan. Continue cooking, without stirring, until thermometer registers 250°F (about 15 minutes).