Cumque pauciores utrubique fierent bellatores, et Persae truderentur ad ultima ni potior ratio succurrisset, impensiore opera procursus temptabatur ex castris, et eruptione subita multitudinis facta, inter armatos qui portabant ignes amplioribus ordinatis, iaciebantur corbes in materias ferreae, plenae flammarum, et sarmenta aliaque ad ignes concipiendos aptissima. Et quia conspectum abstulerant fumi nigerrimae nubes, classico excitante in pugnam, legiones procinctae celeri gradu venerunt, et subcrescente paulatim ardore bellandi, cum ventum fuisset ad manus, repente machinae omnes effusis ignibus urebantur praeter maiorem, quam diruptis restibus quibus e muro iactis implicabatur, virorum fortium acrior nisus aegre semustam extraxit.
Translation :
And when the fighting men on both sides became fewer, and the Persians were driven to the last extremity unless some better plan should suggest itself, a carefully devised sally from the fortress was attempted. A vast throng made a sudden rush, with still greater numbers of men carrying material for setting fires drawn up among the armed soldiers; then iron baskets filled with flames were hurled upon the woodwork, as well as faggots and other things best suited for kindling fires. And because the pitch-black clouds of smoke made it impossible to see, the legions were roused to the fight by the clarion and in battle array advanced at rapid pace. Then, as their ardour for fighting gradually increased and they had come to hand-to-hand conflict, on a sudden all the siege-engines were destroyed by the spreading flames, except the greater ram; this, after the ropes which had been thrown from the walls and entangled it had been broken, the valiant efforts of some brave men barely rescued in a half-burned condition.
Edition :
Ammianus Marcellinus. With An English Translation. John C. Rolfe, Ph.D., Litt.D. Cambridge. Cambridge, Mass., Harvard University Press; London, William Heinemann, Ltd. 1935-1940.