Old-Fashioned Baked Beans

3 cups dried navy beans (Great Northern) -- 1 1/2 lbs.

3/4 pound salt pork

1 medium onion

2 teaspoons salt

1/4 cup brown sugar, firmly packed

2 teaspoons dry mustard

1/2 cup light molasses

1/4 cup ketchup

1. Wash beans, discarding imperfect ones. Cover beans with 2 quarts cold water; refrigerate, covered, overnight. 2.Next day, turn beans and water into 6-quart kettle. 3. Bring to boiling; reduce heat and simmer, covered 30 minutes. Drain, reserving liquid. 4. Preheat oven to 300 degrees. 5. Trim rind from salt pork. Cut pork almost through ,at half-inch intervals. 6. Place onion in bottom after 4-quart bean pot or casserole. Add beans; bury pork, cut side down, in center of beans. 7. Heat reserved bean liquid to boiling. 8. Mix remaining ingredients. Stir in 1 cup boiling bean liquid. Pour over beans. Add boiling liquid just to cover beans--about 1 1/2 cups. 9. Bake covered, 6 hours. Stir once every hour, so beans cook evenly. If they seem dry after stirring, add a little boiling water. 10. To brown top of beans, remove cover for last half hour of baking time.