Frosting for Cake

From 1874:

The whites of two eggs to a half pound fine sugar; beat the eggs to a stiff froth; then add the sugar, and beat until it falls in flakes from the knife. When spreading it on the cake, dip the knife occasionally in cold water. Dredge that side of the cake which rested upon the tin while baking with sifted flour (to remove whatever grease may be left) before spreading the icing.