into a field of grain, or a mountain river whirls along in spate, flattening all the fields, the growing crops and all the labour of oxen, carrying great trees headlong down in its floods while the shepherd stands stupefied on the top of the rock, listening to the sound without knowing 310 what it is.
Powerful simile shows Aeneas's shock and horror at the events unfolding - he is hardly able to understand the extent of what he is seeing. The Greeks as an unstoppable force of nature - and connection back to Aeneas as a shepherd watching the flood race down the mountainside (earlier simile)
