Approximate scale : .in. = 1 foot.
THIS engine is here shown ready for discharge with its bow-string drawn
to its full
The heavy iron-tipped arrow rests in the shallow wooden trough or groove
The trough has a strip of wood, in the form of a keel, fixed beneath
The arrow is laid in the trough before the bow-string is stretched. (A, B, fig. 14.)
The ballista is made ready for use
by turning the windlass. The windlass
As the trough and the arrow are
drawn back together, the arrow can
The catch for holding the bow-string,
and the trigger for releasing it, are
The two ratchets at the sides of the after-end of the trough travel
By this arrangement the trough can be securely retained, in transit,
As the lock and trigger of the ballista are fixed to the after-end of
In this respect the ballista differed
from the crossbow, which it somewhat
These parts of the ballista are
the same in their action and mechanism
FIG. 14 – The Mechanism of the Stock of an Arrow Throwing Ballista.
A. Side view of the stock, with the arrow in the sliding trough
B. Surface view of the stock, with the arrow in the sliding trough before the bow-string is stretched.
C. Section of the fore-end of the stock, and of the trough which slides in and along it.
1 When the bow-string has been released and the arrow discharged, the ratchets are lifted clear of the cogs on the stock of the engine. This allows the trough to be slid forward to its first position as shown in A, B, Fig. 14. It is then ready to be drawn back again for the next shot.
FIG. 14– THE MECHANISM OF THE STOCK
OF AN ARROW-
D. Surface view of the trough, with
the trigger and catch for the bow-
E. Side view, showing the keel (F) which slides along
the slot cut in the
G. Enlarged view of the solid end
of the trough. This sketch shows the
Ballistas were constructed of different
sizes for the various purposes of
The largest had arms of 3 ft. to 4 ft. in length, and skeins of twisted
Judging from models I have made
and carefully experimented with, it is