Fortunato is dressed as a clown (fool) for Carnival. This is symbolic of how foolish Fortunato is and has been. Carnival, itself, is symbolic of celebration and of revelry, and Montressor is reveling in his plot coming to fruition. Later on there is mention of a trowel, which is a representation of the Freemasons and is a bit of symbolism as it is a symbol of Fortunato's death. The cellars, also, are symbolic of the twisted, dark, and poisonous interior of Montressor's mind. Lastly, the mention of Nitre is symboic of a tomb since this is a type of white growth that usually grows in tombs.
