Vintage Orange Cake from 1912

A vintage orange cake from my collection of recipes that was printed in 1912.

Three eggs, their weight in sugar, butter and flour, 1 teaspoon of baking powder, 1 orange, a pinch of salt.

Beat the sugar and butter to a cream; add 2 eggs one at a time, and beat well; then add half the flour, beating well all the time; add the grated rind of the orange and half the juice; then put in remainder of flour and a small teaspoon of baking powder; add the third egg.  Bake 1 hour or longer in a moderate oven.  Ice with the following icing: -Six ounces of icing sugar, enough orange juice to make a thick cream (about 1 ½ tablespoons); warm, but do not let get hot, and pour over the cake.

I baked this cake at 150 degrees celsius in a conventional oven for 40-45 minutes.