It was a town of machinery and tall chimneys, out of which interminable [unending] serpents of smoke trailed themselves for ever and ever, and never got uncoiled. it had a black canal in it, and a river that ran purple with ill-smelling dye, and vast piles of building full of windows where there was a rattling and a trembling all day long, and where the piston of the steam-engine worked monotonously up and down, like the head of an elephant in a state of melancholy madness. in this passage, what animals does dickens compare smoke and machinery to? a serpent and an elephant a chimney and a monster a black canal and a steam-engine a piston and an elephant