Clean and truss it the same as for baking. Stuff the turkey with oysters, bread crumbs, butter and mace, all mixed and seasoned. Put it on the fire in a kettle of water not hot, but slightly warm; do not drop it into boiling water or it will break the skin and spoil the appearance of the turkey. Cover it close, and when the scum rises take it off. Let the boiling continue for one hour, then put the pot containing the turkey on the coolest part of the stove, and let it simmer for half an hour. Serve with oyster sauce in a sauce boat.