Introductory Notes on Ancient Projectile Engines
Of ancient Greek author who have left us accounts of these engines,
Heron (284-221 B.C.) and Philo (about 200 B.C.) are the most trustworthy.
Both these mechanicians give plans and dimensions with an accuracy that
enables us to reconstruct the machine, if not with exactitude at any rate
with sufficient correctness for practical application.
Though in the books of Athenaeus, Biton, Appollodorus, Diodorus, Procopius,
Polybius and Josephus we find incomplete descriptions, these authors, especially
Josephus, frequently allude to the effects of the engines in warfare; and
scanty as is the knowledge they impart, it is useful and explanatory when
read in conjunction with the writings of Heron and Philo.
Among the Roman historians and military engineers, Vitruvius
and Ammianus are the best authorities.
copied his descriptions from the Greek writers, which shows us that the
Romans adopted engines from the Greeks.
Of all the old authors who have described the engines, we have but copies
of the original writings. It is, therefore, natural that we should come
across many phrases and drawings which are evidently incorrect, as a result
of repeated transcription, and which we know to be at fault though we cannot
actually prove them to be so.
With few exceptions, all the authors named simple present us with their
own ideas when they are in doubt respecting the mechanical details and
performance of the engine they wish to describe.
All such spurious information is, of course, more detrimental than helpful
to our elucidation of their construction and capabilities.
It frequently happens that in a mediaeval picture of one of these machines
some important mechanical detail is omitted, or, from the difficulty of
portraying in correctly, is purposely concealed by figures of soldiers,
an omission that may be supplied by reference to other representations
of the same weapon.