Tomato and Rice Soup

3 cups water
2 beef bouillon cubes
1 cup chopped onion
1/2 cup chopped celery
1/2 cup uncooked rice
1 large can of tomatoes
1 tablespoon butter
1 teaspoon salt
1/2 teaspoon chili powder

Saute onion and celery in butter; add the rest of the ingredients and bring to a boil. Reduce heat and simmer 20 minutes or until rice is tender.