How fast or slow the line actually moves, or its cadence, is super important in connecting sound and sense in this poem. For example, the line moves slower when speaking about Ajax than when speaking of the flying Camilla. The uses of stresses and elisions (removal of syllables, as in "o'er" instead of "over") changes the cadence and causes us to treat even the commas (or caesuras) in the middle of the lines differently. For Ajax in lines 9-10 the comma in the middle of the line feels like a weighty pause, because he's struggling to pick up a heavy rock. For Camilla in lines 11-12, the comma feels like we are just giving a quick pause while she jumps up in the air and flies over a little crack in the line.