Scrub the clams. Place them in a large kettle with 1 cup water, cover, and cook over medium high heat till they open. Remove the clams, strain the liquid, and chop the clams.

Fry out the salt pork in a skillet, and when crisp, transfer to absorbent paper.

Pour off all but 2 tablespoons fat from the skillet and sauté the onion slices lightly for 4 to 5 minutes, turning them with a wooden spatula several times.

Parboil the potatoes 5 minutes in salted water to cover.

Arrange the onions in the bottom of a heavy saucepan and top with a layer of half the potatoes. Add the salt pork pieces, then the chopped clams, then another layer of potatoes and salt and pepper. Add the boiling water and cook 10 minutes.

Add the scalded milk and bring to a boil. Add the soaked crackers and liquid the clams cooked in. Finally add the flour and butter kneaded together. Bring to the boiling point and correct the seasoning.

Serve in hot chowder bowls.