Guns and cannon are a key image for the enemy, for the threat of death. Tennyson doesn't waste much time telling us why this fight is happening, or who's attacking who. Maybe his readers at the time already knew the story, but for folks today the details are pretty sketchy. There is one mention of the "Cossack and Russian" soldiers, but mostly all we hear about is this big scary wall of guns.
- Line 6: Here the guns are just an idea, a destination for the Brigade. They symbolize the challenge of war, the call to heroic deeds, the threat of the enemy. It's also just seems like a crazy idea, to charge a bunch of horses toward a wall of guns.
- Lines 18-20: Now the guns (here he calls them "cannon") are very real and very deadly. At the beginning of the charge, the Brigade was headed toward the guns, but now they are completely surrounded by them. They are a totally faceless enemy, just a threat from every side. We don't know yet who's behind them or why.