General Remarks
In all icing that is not boiled it is necessary to use “icing” sugar, which is very fine and flour-like in appearance.
Plain Icing
Whites of 2 eggs
¹⁄₂ lb. icing sugar
Flavouring, lemon, vanilla, or almond, etc.
Break the whites into a good sized dish. Add two heaping table-spoons of sugar and stir it in steadily. Beat for a few minutes. Add the sugar gradually, beating well. The making should take about half-an-hour. When thick enough it should not run together again after being cut with a knife. If flavoured with lemon juice, a little more sugar should be added or the icing will not be stiff enough.
Pour the icing on to the cake by large spoonfuls and allow it to settle itself as much as possible. When using a knife, dip it first in cold water.
Ice a cake two or three hours before it is to be eaten. It can be set to harden in a moderate oven for five minutes if needed quickly: but it is best to dry it slowly in a warm, sunny place.
Boiled Icing
1 cup powdered sugar
1 cup water
Whites of two eggs
Flavouring
Boil the sugar and water together until it spins a thread from a spoon. Then take the syrup off the fire and pour it into a basin. Add the whites (beaten to a stiff froth) to it gradually, beating hard all the time. Continue beating until the mixture is cold. Add flavouring.