Melt 1 cup sugar in a large pot while the milk is scalding in a double boiler. When the sugar is melted to a rich yellow, add the hot milk all at once, stirring. It will boil up quickly so be sure to use a good-sized pot. Add 2 cups sugar to this mixture, stirring until dissolved; cook until it forms an almost hard ball (238°F). Just before it is done, add grated orange rind, salt, butter and pecans. Beat until creamy, drop by spoonful on waxed paper or pour onto a buttered platter to cool.