By a Meadow Gate

[dukealien]

By a Meadow Gate

Already, the hum, drums  "Already" is a good way to engage the reader, start in the middle of action to be described or imagined later
heard out on the way  nice ambiguity - is it the speaker on *his* way, or "way" as the lane or road nearby

like some copper mill, I tolled  
heating up its furnace  I read this as implied "heating up (its) furnace" for which tolling is a good description of how a big boiler bongs, slow metronome

nodding donkeys bray  implied (at), but not necessarily...
the rising of the sun  which leads to the image of the herd (line 2 homonym)  actually bringing sunrise to pass

In basic critique, this accomplishes a lot with simple, somewhat disconnected descriptions:  it definitely shows without telling (a compliment derived from the admonition "show, don't tell").  The title is not necessary, but does provide an initial image; it doesn't directly connect with the body of the poem, but does contrast in its stationary nature with the "Already" motion that follows.

I like this.  The phrases mostly describe sounds; perhaps (visual) images could be added to clarify gleam of copper, dewy wire meadow fence, shaggy  texture of donkeys.   As a tone picture, it's effective but could use at least the hint of a story connecting its sonic episodes or environments.  Or you could add more sounds to build a story (crackle of straw under mill-worker's brogans, creak as the meadow gate closes).