In "A Christmas Carol," Marley's chains are an important symbol in the story. What are they made of? What is hanging from them? What might these...

Marley's chain is
symbolic of his guilt as well.  He says that he forged it during his life, of his own free
will.  He is guilty, indeed, of heavy sins against his fellows, sins that he chose to commit,
and guilt that he chose to accrue.  In fact, we see this symbolism in the ghosts that Scrooge
sees outside the window, too.  The narrator says that 

Every one of them wore chains like Marley's Ghost; some few (they might be guilty
governments) were linked together; none were free.  Many had been personally known to Scrooge in
their lives.  He had been quite familiar with one old ghost, in a white waistcoat, with a
monstrous iron safe attached to its ankle, who cried piteously at being unable to assist a
wretched woman with an infant, whom it saw below, upon a door-step.  The misery with them all
was, clearly, that they sought to interfere, for good, in human matters, and had lost the power
for ever.

All of these individuals are guilty as well,
guiltyapparentlyof failing to help their fellow human beings while they were alive, and now
their chains symbolize that guilt.  Marley's chains contain ledgers and cash boxes, indicating
the specific ways in which he is guilty of failing humanity; likewise, the ghost here has a
chain containing a huge iron safe, which probably indicates that he failed his fellows by
hoarding his money rather than helping those in need (like Scrooge, which explains why Scrooge
recognizes him).  Since these ghosts are all miserable because they cannot now help the living,
it is reasonable to infer that this is what causes their guilt: their failure to help their
fellows when they had the chance.  This is why Scrooge's chain would be so much longer and
heavier than Marley's; he's had seven more years of denying people help, and seven more years of
guilt for it.