Quarter unpeeled orange; remove seeds and slice thin. In an 8 to 10 quart kettle combine first 3 ingredients and 2 cups water. Bring mixture to boiling. Reduce heat; simmer until apples are tender, about 10 minutes. Add sugar. Bring to a full rolling boil, stirring constantly. Continue cooking and stirring until candy thermometer reaches 220ºF. Remove from heat; skim off foam. Pour into hot sterilized jars; seal. Makes 6 half-pints.