Throughout "As I walked Out One Evening," Auden sets up comparisons between the manmade and the natural. It's not quite East Coast vs. West Coast, but Auden makes the rivalry pretty interesting nevertheless. These two realms seem to be in a kind of tug-of-war for supremacy. Who do you think will win? Shmoops money is on that river. After all, it does get the last word.
Lines 1-4: From the very first stanza, we can see this juxtaposition of the manmade and the natural. Here we have it in the rhymed end words in lines 2 and 4, street and wheat. The words share placement (they both hang there at the end of their lines) as well as sound (yup, the rhyme). Street is definitely from the manmade realm, while wheat is decidedly natural. But they are in the same location in their respective lines and they sound darn similar. Hmmmm. What could W.H. be telling us? Perhaps these two realms, like these two words, have some essential similarities. Shmoop bets it has something to do with the fact that Time ultimately rules over both of them.
Lines 5-8: Here we go again. This time, the end words river and railway stand out. As before, one word represents the natural world (river) and the other word represents the manmade world (railway). Rivers and railways (like street and wheat) are definitely different things. But here again, just as the words have similarities in placement and sound (those initial Rs), rivers and railways have similarities, too. Both are, in a sense, linear. They move from point A to point B. They can be used to travel, and as images they can represent the journey or life. If we are talking journey of life, Time is going to come up. Is this starting to sound familiar?
Lines 12, 41-42: Here's a change. Instead of the manmade and the natural words having separate lines, now they are sharing lines. Looks like the connection that Auden was suggesting with those rhymes is becoming even stronger. The separation between the manmade world and the natural world seems to be vanishing. Salmon belong in the river, but now they are "in the street." And they certainly shouldn't be singing. Glaciers have about as much business being in cupboards as deserts do in the bedroom—which is to say none at all. By mixing these two realms so absurdly, Auden is reinforcing that idea that Time makes no distinction between the two realms. In Time's eyes, everything is the same.