Roman siege engines BC, and surrounded by Roman fortifications. As was standard siege technique at the time, "ballistae" were placed up in the towers with other soldiers armed with either bows or slings. The onager was a post-classical Roman siege engine, which derived its name from the kicking action of the machine, similar to that of an onager (wild ass). It is a type of catapult that uses torsional pressure, generally from twisted rope, to store energy for the shot. The onager consisted of a frame placed on the ground to whose front end a vertical frame of solid timber was rigidly fixed;
Emotional support animal support animals to one animal per ticketed passenger. The main controversies are the behavior of some animals, harms to other people, the problem of widespread fraud, and the open scientific question about whether emotional support animals provide significant benefit. An emotional support animal may cause problems that a trained assistance dog may not. For instance, due to the lack of training, an emotional support animal may bark at and smell other people, whereas service dogs are trained not to do so. People with a different type of invisible disability – allergy to animal dander – have suffered from allergic attacks