Giv Fires the Wooden Barricade

From B12.15, The Snowstorm Campaign. It illustrates B12.15.37–40:

B12.15.37
He crossed the Kasa Rud with toil and pain,Through ice and snow that veiled the frozen plain.
B12.15.38
When he had reached the barricade of wood,Its breadth and length beyond all measure stood.
B12.15.39
He lit the arrowhead and shot it high;It struck the pile and flames consumed the sky.
B12.15.40
For three full weeks, heat, flame, wind, smoke becameA barrier through the wood no force could tame.