Rhubarb and Barley Pudding

One pint of milk, one pint of water, 3 oz. pearl barley, 1 lemon, 1 lb. rhubarb, sweetening to taste, ½ oz. margarine and cinnamon. Well wash the barley, put it with the milk and water into a double pan, simmer two hours till tender. When it is cooked, mix it with the grated rind of the lemon, and add sweetening. Grease a piedish, put in a layer of the cooked barley, then a layer of washed rhubarb, cut in short lengths, then more barley, etc., till the dish is full, ending with barley. Put a few shreds of margarine on the top and a very light dust of cinnamon, and bake in fairly hot oven till the rhubarb is soft, and the surface browned. Can be served with custard if liked. A very nourishing pudding.