This section is from the book "Preserving And Pickling", by Mary M. Wright. Also available from Amazon: Preserving and Pickling: Two Hundred Recipes for Preserves, Jellies, Jams, Marmalades, Pickles, Relishes and Other Good Things.
Marmalades differ from preserves in that the fruit is usually passed through a sieve or colander, or else mashed to a pulp with a wooden spoon, instead of being left as whole as possible. In making marmalades the fruit is cooked longer than in the making of preserves. As in the making of preserves many delicious marmalades may be made with combined fruits. We give here a variety which will likely suggest others equally as good.
Peel and seed the peaches, and stew in a little water until tender. To each pint of this peach pulp add three-fourths of a pound of sugar, and about a fourth of a cupful of water. Boil down to a thick marmalade, stirring constantly to prevent burning.
Select, wash and soak overnight three pounds of fine large prunes. Stew slowly until tender, then pass through a food chopper or a sieve. To each pint of the pulp add a cupful of stewed cranberries, and a pound of sugar. Cook to a marmalade, stirring enough to prevent sticking, and to make the marmalade smooth.
In making this marmalade use equal parts of pears and grapes. Stew the grapes until soft, then pass through a coarse sieve. Add to this grape pulp an equal quantity of stewed pear pulp. Add three-fourths of a pound of sugar to each pint of pulp. Cook until the right consistency for marmalade, and fill jars.
For this marmalade use the red cherries and red currants. Add just enough water to prevent burning, and simmer slowly until tender; then pass through a coarse sieve or colander. Place in a preserving kettle, and add to each pint of pulp one pound of sugar. Boil slowly to the consistency of marmalade; then fill glasses or jars and seal.
Choose nice, fine-flavored pears. Pare, and cut up into bits, and drop into cold water. When ready to use drain, weigh, and to each six pounds of the fruit add one lemon sliced very thin. Pour over just enough water to cover, and simmer slowly until tender. Pass the fruit through a coarse sieve; then add the sugar, using three-fourths of a pound of sugar to each pint of pulp. Heat the sugar in the oven before adding it. Cook slowly, stirring almost constantly until it forms a thick marmalade. Pour into jars or glasses.
The small yellow tomatoes are nice for this purpose. Peel and measure, and to each pound of fruit add a pound of sugar. To each seven pounds of the fruit use the juice of a half dozen oranges, and the juice of three lemons. Use the grated rind of three of the oranges and one of the lemon, using only the yellow part, as the white pith is bitter. Boil to the consistency of marmalade, stirring constantly. Fill preserve jars and seal.