| Quote #1
And then — prodigious step
Around a Pile of Mountains — (4-5)
The speaker depicts the train on a scale larger and more powerful than a mountain range – pretty heavy duty. It's described as "prodigious," and it is clearly something of a prodigy, as it's able to lightly "step" around a "pile" of mountains like a child stepping carelessly around a pile of toys.
| Quote #2
And supercilious peer
If you had any doubts about the train's strength relative to our own, let them be erased here. The train clearly views itself as superior as it passes by human habitations, a sentiment betrayed by the adjective "supercilious."
| Quote #3
And then a Quarry pare (8)
As if the train didn't seem powerful enough already, the speaker demonstrates her awe of its physical strength here – it easily "pares," or slices, through rock as it passes through a tunnel.