Fill bottom crust with a layer of raspberries. Top with 1/2 cup sugar and 3 tablespoons tapioca. Add another layer of berries. Top with 1/2 cup sugar and 2 tablespoons tapioca. Dot with butter. Put on a top crust. Cut slits in crust. Bake 10 minutes at 450 degrees and then another 35 minutes at 350 degrees. Makes a deep 9" pie.