Approximate scale : .in.=1 foot.
This engine is here shown with its bow-string only slightly drawn along its stock by the windlass
one last described. (Fig.13.)
The difference is that it propelled a stone ball instead of a large
The bow-string was in the form of a broad band, with an enlargement
The description given of the mechanism and management of the engine
Small engines with arms about 2 ft. in length and skeins of cord about
There is little doubt that the large stone-throwing ballista of the
A. Surface view, with the stone in position.
B. Side view, with stone in position.
C. Front view of the stone as
it rests in the trough against the
D. Enlarged view of the solid end of the sliding trough. This
Compare with figs. 13, 14,, for further explanation of details.
1 The balls used by the ancients in their catapults and ballistas were often formed of heavy pebbles enclosed in baked clay, the reason being that balls made in this way shattered on falling and hence could not be shot back by the engines of the enemy. The ballistas for throwing arrows, and those employed for casting stones, were fitted with axles and wheels when constructed for use in field warfare.
From Il Codice Atlantico, Leonardo da Vinci, 1445 1520
By turning the spoked wheels, the screw-worm revolved the screwed
bar on which the lock A traveled. The lock, as may be seen, worked
to or fro in a slot along the stock of the engine. In the illustration
the bow is fully bent and the man indicated is about to discharge
the engine. After this was done, the lock was wound back along the screw-bar
and the bow-string was hitched over the catch of the lock preparatory to
bending the bow again.
No artist before his time ever had such comprehensive talents, such profound skill or so discerning a judgment to explore the depths of every art or science to which he applied himself. JOHN GOULD, Dictionary of painters, 1839.
From the above eulogy we may conclude that the drawings of ancient siege engines by Leonardo da Vinci are fairly correct.