Cook salt port until light borwn. Drain off excess fat. Add onions and cook until tender but not brown in a large kettle, combine clams and juice, pork, onions, potatoes, and water. Boil 10 minutes. Season to taste. Pour hot into hot pint Ball jars, leaving 1-inch head space. Adjust caps. Process pints 1 hour and 40 minutes at 10 pounds pressure. For New England Chowder.....add 2 Tbs butter and 2 cups milk to each pint Clam Chowder before heating for serving.