How does W.W.Jacobs make "the Monkey's Paw" an effective ghost story?

The story commences with a sudden value of tension, terror and a sense of eeriness in the atmosphere. The setting is described as a "cold and wet night"; this is entered into the story to give the readers an immediate sense of uncanniness and terror. However, promptly after that build of tension Jacobs begins to describe the living conditions inside the house. He describes this as a warm and cosy home. This description includes these …

…and "don't you think you might wish for four pairs of hands for me?". Mrs. White is obviously making fun of the monkey's paw even though the feeling that Jacobs had previously contrasts the feeling that about it was one of fear and anxiousness. I think this was used excellently because once again our tension is going high and low, we have total mixed emotions and are confused about the ora of the monkeys paw.