How To Make Plum Jam!

How to make plum jam straight off the fruit tree to a jar. Using a 1969 ball blue book recipe. 4 pounds of plums 1 1/2 cup of water 1/4cup of lemon juice 6 cups of sugar Seed and chop plums add the rest of the ingredients boil to the gelling temp 220 degrees for around 20 to 30 minutes stirring often.