The description given of the mechanism and management of the engine
for throwing arrows can be applied to the construction and manipulation
of this form of balista, which was also made of large and small dimensions.
Small engines, with arms about 2 ft. in length and skeins of cord about
4 in. in diameter, such as those I have built for experiment, will send
a stone ball, 1 lb. in weight, from 300 to 350 yards.
There is little doubt that the large stone throwing ballista of the
Greeks and Romans was able to project a circular stone, of 6 to 8 lbs.
weight, to a distance of from 450 to 500 yards. 1
Fig. 10. - The Sliding Trough of the Stone Throwing
A. Surface view, with the stone in position.
B. Side view, with the stone in position.
C. Front view of the stone as it rests in the trough against the enlarged
centre of the bow string.
D. Enlarged view of the solid end of the sliding trough. This sketch
shows the ball in position against the bow string; the catch holing the
loop of the bow string, and the pivoted trigger which, when pulled, releases
the catch. One pair of the ratchets which engage the cogs on the side of
1 The balls used by the ancients in their catapults
and ballistas were often formed of heavy pebbles inclosed in baked clay,
the reason being that the balls made this way shattered on falling an hence
could not be shot back by the engines of the enemy. The balistas for throwing
arrows, and those employed for casting stones, were fitted with axles and
wheels when constructed for use in field warfare. (Pages 260, 273, 300,
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Parts Shopping List
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