Welcome to Sprite SWF. At this site I have provided a copy of a text on onagers, trebuchets, ballista and other catapults that was written in 1903 by Sir Ralph Payne-Gallwey. It is taken from his book titled, ‘The Crossbow.’ This document is available for free on the internet archives. I have provided a cleaned up copy for easy reading, searching and quoting.The copyright on this document has long since expired so please feel free to copy, quote and use this text however you wish.
It is older, however and some of the information is known to be out-of-date or just plain incorrect. It is still one of the best and most interesting sources of information on medieval siege-engines out there. The author built some of these models himself to test them out. His largest weighing in at one and a half tons!