Step 1

In a large soup pot, add the clams and 4 cups of water. Bring to a simmer over moderately high heat, cover and cook until the clams start to open, about 4 minutes. As the clams open, transfer them to a large bowl to cool; discard any clams that do not open. Strain the clam liquid into a large measuring cup (there should be 5 1/2 cups of liquid). Add enough chicken broth to make 7 1/2 cups. Remove the clams from their shells and coarsely chop them.

Step 2

Wipe out the soup pot and place over moderate heat. Add the bacon and cook, stirring occasionally, until crisp, about 12 minutes. Add the onions, carrots, celery, 2 teaspoons of salt, cayenne and the bay leaf. Cook until the vegetables are soft, about 10 minutes. Stir in the flour and cook until it begins to stick to the bottom of the pan, about 2 minutes. Stir in the clam-broth mixture and bring to a boil. Add the potatoes, corn and Old Bay and simmer over moderately low heat until the potatoes are tender, about 15 minutes. Stir in the half-and-half, parsley, Worcestershire sauce and Tabasco. Remove from the heat and stir in the clams. Discard the bay leaf and season the chowder with salt and pepper. Ladle the chowder into bowls and serve.