To prepare watermelon rind, cut rind into 2- x 1-inch pieces. Trim green skin and pink flesh from rind. Place prepared rind in large kettle and add salt and enough boiling water to cover. Simmer until tender. Drain and chill rind in very cold water at least 1 hour or overnight in refrigerator. Combine vinegar, sugar and mixture of cinnamon, cloves and gingerroot tied in cheesecloth. Bring to boil and boil 5 minutes. Drain watermelon rind and add to syrup. Simmer until rind becomes translucent, about 10 minutes. Remove and discard spices. Pack rind and syrup into hot sterilized quart jars, leaving 1/4-inch head space. Adjust lids and process in boiling water bath 20 minutes.
