A new reconstitution of the manubalista of Xanten

[Emmanuel]

Thanks for all. If some body can give me some informations on arrows. I'am working on it. If I follow the system of Vitruvius. The arrow must be of 9 times the diameter of the foramen of the manubalista so 27 centimeters. But I have a problem because of a photographywhere we can see some romans bowmen with the arrows posed on their hats... Il this case, 27 is too long.