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.
Raspberries, blackberries, strawberries, currants, peaches, pears, apples - all make delicious jams when combined with rhubarb. In making strawberry-rhubarb jam take one part rhubarb and two parts strawberry. Use only the tender ends of the rhubarb. Use a pound of sugar to each pound of fruit. Place the strawberries on platters and cover with the sugar, and let the fruit stand overnight. In the morning pour off the juice into a preserving kettle, and add the rhubarb, and let boil until it begins to get thick, then add the strawberries, and cook until they are heated through. Pour into jars or glasses and seal. This makes a pretty jam, as well as a delicious one. Bed raspberry jam can be made in the same way. In making blackberry-rhubarb jam use about equal parts of each kind of fruit. A delicious preserve may be made with equal parts of pineapple and rhubarb, using a pound of sugar to each pound of fruit.