Wash, blanch, peel and pit nectarines; wash the oranges. Remove the peel from 1½ of the oranges and discard it.
2
Put the nectarines and the peeled and unpeeled oranges through a meat grinder or slice and dice very thinly. There should be about 4½ cups.
3
Place the fruit in a preserving pan, add 4½ cups of sugar and bring slowly to a boil. Boil rapidly, uncovered, for about 30 minutes, stirring frequently. Skim off foam with a metal spoon. Ladle into hot, sterilized jars and seal immediately.