Who guides us through these dirty streets and dingy apartments? The speaker in the poem stays detached from the images for most of the poem, serving as a narrator to the reader, whom he (or she) addresses directly at points.
While the speaker might not seem to be physically present, he (we'll just use "he" here for simplicity) sure seems to know about us. In stanza 1, the speaker places us inside the city on a rainy night, and later follows us home as we get ready for bed. They even know the way we curl our hair.
But we aren't the only ones that the speaker has special knowledge about; the speaker knows that the cab horse is "lonely." Yep, this person is a mind-reader. In stanza 2, our speaker knows what we are thinking, and then what the street is thinking in stanza 3. All this knowledge would suggest that the speaker is omniscient, which makes him able to time-travel in the last stanza and see those ancient women gathering fuel.
The identity of this time-travelling speaker may not be apparent, but his opinion of the city and the people within it is pretty clear. They frequently call the city "grimy," "stale" and without conscience. It's clear the speaker doesn't have the best opinion of the way the city's inhabitants live. He seems to know everything, and isn't very pleased by that knowledge.