The Batavians had raised a tower two stories high, which they brought up to the Praetorian gate of the camp, where the ground was most level. But our men, pushing forward strong poles, and battering it with beams, broke it down, causing great destruction among the combatants on the top. The enemies were attacked in their confusion by a sudden and successful sally. All this time many engines were constructed by the legionaries, who were superior to the enemy in experience and skill. Peculiar consternation was caused by a machine, which, being poised in the air over the heads of the enemy, suddenly descended, and carried up one or more of them past the faces of their friends, and then, by a shifting of the weights, projected them within the limits of the camp.

From Tacitus’ Annals and Histories, New York: Everyman’s Library, 2009 (first published in 1908), p. 571.