Get out the microscope, because we’re going through this poem line-by-line.
And Thee, across the harbor, silver-paced
As though the sun took step of thee, yet left
- The speaker addresses the bridge directly, using the old-fashioned "Thee" like you'd find in a Shakespeare play.
- The poem is called "To Brooklyn Bridge" because it is literally addressed to the bridge: "Thee."
- The bridge is across New York harbor from where the speaker is.
- The bridge has a silver "paces" or steps. This is a tricky image: the speaker isn't talking about stairs, but about the impression of forward movement in the bridge's appearance.
- A "pace" is also a kind of platform, so the metal bridge platform looks silvery.
- It looks like the sun walked over ("took step of") the silvery bridge – or that the bridge is like a footprint impression made by the sun as it passes.
Some motion ever unspent in thy stride,--
Implicitly thy freedom staying thee!
- The bridge looks like a moving thing, even though it doesn't move.
- When the sun moved over the bridge, it left the appearance of "motion" in the bridge.
- You can guess what he's talking about – suspension bridges like this could "move" because they just hang in the air with those curvy suspenders. They play tricks on the eyes.
- The bridge is active and alive, not passive and dead.
- But the bridge doesn't actively move – it is "stayed" or stopped. In terms of physics, it has potential but not kinetic energy.
- There is a kind of contradiction in line 16: the bridge's freedom prevents it from moving.
- Maybe the speaker means that the bridge hangs "free" in the air because of its wires, and those wires also keep it from moving.
- At any rate, he has established the bridge as a symbol of freedom.