In a heavy saucepan cook the bacon, the onion, and the celery in the butter over medium-low heat, stirring, until the vegetables are softened, add the milk, clams with the liquid, potatoes, salt and pepper.
Simmer the chowder, stirring occasionally, for 15 minutes, or until potatoes are tender.
Stir in the green onions.
Servings: (about 8 cups