Flavius Josephus, The Wars of the Jews
William Whiston, A.M., Ed.

[222] And now, when Josephus saw this ram still battering the same place, and that the wall would quickly be thrown down by it, he resolved to elude for a while the force of the engine. With this design he gave orders to fill sacks with chaff, and to hang them down before that place where they saw the ram always battering, that the stroke might be turned aside, or that the place might feel less of the strokes by the yielding nature of the chaff. This contrivance very much delayed the attempts of the Romans, because, let them remove their engine to what part they pleased, those that were above it removed their sacks, and placed them over against the strokes it made, insomuch that the wall was no way hurt, and this by diversion of the strokes, till the Romans made an opposite contrivance of long poles, and by tying hooks at their ends, cut off the sacks. Now when the battering ram thus recovered its force, and the wall having been but newly built, was giving way, Josephus and those about him had afterward immediate recourse to fire, to defend themselves withal; whereupon they took what materials soever they had that were but dry, and made a sally three ways, and set fire to the machines, and the hurdles, and the banks of the Romans themselves; nor did the Romans well know how to come to their assistance, being at once under a consternation at the Jews' boldness, and being prevented by the flames from coming to their assistance; for the materials being dry with the bitumen and pitch that were among them, as was brimstone also, the fire caught hold of every thing immediately, and what cost the Romans a great deal of pains was in one hour consumed.