Who are the children under the ghost's robes?

The children represent the abject poverty and the neglect of man to what should be most precious to him.

They are Man's," said the Spirit, looking down upon them. "And they cling to me, appealing from their fathers. This boy is Ignorance. This girl is Want. Beware them both, and all of their degree, but most of all beware this boy, for on his brow I see that written which is Doom, unless the writing be erased. Deny it!" cried the Spirit, stretching out its hand towards the city. "Slander those who tell it ye. Admit it for your factious purposes, and make it worse. And abide the end."