When Jacob Marley appears to Scrooge, he is weighed down by a chain made up of cash-boxes, keys, padlocks, ledgers, deeds, and heavy purses wrought in steel—that is, the chain around his middle consists of things he valued while he was alive, and now serves as a means of eternal punishment. The chain symbolizes his regrets, and the fact that it’s something Marley himself “forged in life” confirms that he is the one responsible. The ghosts outside the window are wearing their own chains symbolic of the sins they committed in life, and Marley tells Scrooge that he is currently forging his own.
The Children of Ignorance and Want
The Ghost of Christmas Present introduces Scrooge to a pair of children sheltered beneath his robe, both of them starving and pitiable. They are, according to the ghost, called Ignorance and Want, and clearly symbolic of the consequences of the very concepts for which they are named. That is, ignorance of the suffering of the poor and relentless desire for material gain leads to income inequality and, as exemplified here, starving children.
The light coming out of the Ghost of Christmas Past symbolizes the memories Scrooge wishes to forget, and the knowledge he would gain from experiencing and processing them. Indeed, Scrooge attempts to extinguish the light by using the ghost’s hat as a candle snuffer. However, the light appears inextinguishable—even when Scrooge forces the cap on his head, light still filters out from the bottom, suggesting Scrooge can’t deny, forget, or ignore events of the past; instead, he must bear witness.