File:Ballista bolt heads.JPGDescriptionBallista bolt heads.JPG Iron ballista bold heads. Photograph was taken in the Somerset County Museum in Taunton on 29-Oct-05. Date 31 October
File:Roman pilum (FindID 824697).jpgmaximum diameter of 7mm. It weighs 9g. The head alone measures 24mm in length.It is one of two ballista bolt heads of Manning's (1985) Type 1 found at Piercebridge;