*To prepare watermelon rind, remove dark green peel from watermelon rind and discard. Cut rind into 2- x 1-inch slices.
DAY 1 ? Layer watermelon rind and salt in large crock, glass or stainless steel bowl. Add 4 cups of cool water. Place large clean inverted plate on top of rind and weigh down with two or three quart jars filled with water and capped. Cover with plastic wrap or a clean towel and refrigerate for 8 hours or overnight.
DAY 2 ? Transfer rind to colander placed over a sink. Drain and rinse in cool running water. Drain and rinse again. Drain thoroughly. Combine rind with remaining 4 cups cool water in large stainless steel saucepan. Bring to boil over medium-high heat. Reduce heat and boil gently until rind is fork-tender, about 10 minutes. Drain and set aside. Combine sugar, vinegar and cinnamon stick halves in a clean large stainless steel saucepan. Bring to boil over medium-high heat, stirring to dissolve sugar. Reduce heat and boil gently for 5 minutes, until cinnamon has infused liquid. Add drained rind and return to boil. Reduce heat and boil gently, stirring occasionally, for 1 hour, until watermelon is translucent. Discard cinnamon sticks. Prepare boiling water canner. Heat jars and lids in simmering water until ready for use. Do not boil. Set bands aside. Pack hot rind into hot jars leaving 1/2 inch headspace. Ladle hot pickling liquid into jar to cover rind leaving 1/2 inch headspace. Remove air bubbles. Wipe rim. Center lid on jar. Apply band until fit is fingertip tight. Process jars in boiling water canner for 10 minutes, adjusting for altitude. Remove jars and cool. Check lids for seal after 24 hours. Lid should not flex up and down when center is pressed. Makes about 4 to 5 (16 oz) pints