Put the sugar and water into a pan, dissolve the sugar slowly in the water and when quite dissolved bring to boiling point.
Boil to 240° F. without stirring.
Brush down the sides of the pan with a brush dipped in cold water and remove scum as it rises.
Pour on to the stiffly beaten egg white, beating all the time.
Continue beating until the icing begins to thicken and coats the back of a spoon thickly.
Pour quickly oven the cake, spread with a palette knife and work up the icing in swirls