A simile is a literary device used to compare or contrast two things. When irony is also being used a simile could completely change semantic context and this is why it can be used to compare or to contrast depending on what is being said.
The simile usually uses the prepositions "like" or "as". An example of a simile would be "Your eyes are blue like the ocean.", or "You are cold as ice."
In A Christmas Carol there are several instances of smile that are also great opportunities for the characters to express their emotions, particularly in a story where the main character will undergo dynamic changes. Phrases such as:
I am as giddy as a drunken man
I am as merry as a school boy
I am as happy as an angel
Are good examples of simile where the character gets to explain the extent to which an event has made a mark in his or her life.
The use of "like" is mainly geared toward a physical comparison. In the case of the ghost of Old Marley, the chain that was attached to the ghost reminds the narrator of a tail, sort of insinuating that this apparition in front of him may or may not demon-like. To add depth to the narrative, and to add mystery and horror to the tone, the chain is described just as such
It was long and wound around him like a tail
Certainly to a reader of Dickens's time, this description would have been powerful, as it was during the Victorian period that Gothic literature flourished with the publications of Dracula, Frankenstein, and the likes. Therefore, Dickens used simile to add that "dash" of Gothic imagery that works so well to create the mood of this particular moment in the story.
A simile is a comparison of two UNLIKE objects using the words "like" or "as". An example would be...... The girl is as pretty as a picture. the girl is being compared to a picture. Two unlike objects --- girl and picture are being compared.
In A Christmas Carol, the very first paragraph gives you a famous simile. It says
"Old Marley was as dead as a door-nail" (pg 5)
The narrator goes on to explain that he doesn't really know how dead a door-nail can be -- that a coffin nail might be more appropriate, but he uses for turn of phrase "dead as a door-nail"
Another simile is when Scrooge enters his home. He has seen Marley's face and is denying that fact. He slams the door shut.
"The sound resounded through the house like thunder" (pg 15)
Here you are comparing the sound of a slamming door to thunder.
When he sees Marley's ghost, he notices the chain coiled around him
"It was long and wound around him like a tail..." (pg 17)
This compares the chain to a tail.
A simile is used in literature to compare two things using "like" or "as." These things can be quite different, but they can also be similar (a sound appearing like thunder).
In A Christmas Carol by Charles Dickens, similes are frequently used. When Scrooge is visited by the Ghost of Christmas Past, he visits the scene of a party he once attended as a young man. His old boss, Mr. Fezziwig, is dancing in the scene. His calves are described as appearing to emit light, so that "they shone in every part of the dance like moons." Dickens compared the light of the moon to the light that seemed to come from Mr. Fezziwig's legs.
Later in the story, Scrooge observes a scene from Bob Cratchit's house. Mrs. Cratchit asks her husband how Tiny Tim behaved in church. Bob Cratchit tells her that he was "as good as gold." Dickens compares Tiny Tim's behavior to a valuable metal to describe it as excellent.