Slice very thin and seed twenty-four small, well - flavored oranges, or twelve large ones, and two lemons. Measure, and if there is less than six pints of juice, add enough water to reach this amount. Some persons consider that it improves the flavor of the marmalade to slice one grape-fruit with this number of oranges. Let the fruit stand in a covered earthen jar or bowl for several hours or overnight. Heat it slowly in a preserving kettle and simmer gently until the orange-peel is tender. Stir in then six pounds of granulated sugar (this is allowing a pound of the sugar to a pint of the juice) and boil until the skin looks clear and the marmalade is jelly-like. Test it by cooling a little in a saucer to see if it has reached the right stage. Let it cool before putting it up in glasses as you would jelly.