ample > broad

3 And, her sword's point directing forward right, 4 Assailed the flame, which eftsoons gave place,

eftsoons > thereupon; forthwith

5 And did itself divide with equal space,

with equal space > [equally]

6 That through she passed; as a thunderbolt

That > [So that]

7 Pierces the yielding air, and does displace 8 The soaring clouds into sad showers melted;

sad > heavy

9 So to her yielded the flames, and did their force revolt.