In a bowl, beat eggs until very light. Add salt, flour and milk; beat well. Thoroughly rub bottom and sides of a 10-in. cast-iron or other heavy skillet with butter. Pour batter into skillet. , Bake at 450° for 15 minutes. Reduce heat to 350° and bake until set, 5 minutes longer. If desired, remove pancake from skillet and place on a large hot platter. Dust with confectioners' sugar and garnish with lemon. Serve immediately.