it cleaves the air (1) and drives straight forward, whereas if it is light the air bears it up and it rises.
He said: The proof (2) of this is that a vessel, when heavy, sinks in water, but when light, floats upon it; and the air stands in the same relation to the arrow as water does to the ship.
Others rejected this argument and said: We observe that an arrow (3) shot flush from a stiff bow on a perfectly wind-still day must inevitably rise above the level of its point of release. The evidence is to stretch a rope crosswise at the halfway mark on the ground (4), exactly level with the arrow’s point of departure, then shoot a flush arrow from a stiff bow; the arrow is certain to pass (5) above that rope.
Another group among them said: What has been verified in our experience concerning the arrow’s ascent and descent is that its flight is completed only through three factors:
- the archer’s own body and strength;
- his bow;
- his arrow.
Each of these constitutes one third of the cause. The proof is that you may take a stiff, fully-strung bow that you cannot ordinarily shoot from, nock an arrow, draw it so that you bend (6) the string only slightly toward yourself without bending the bow itself, then release; the arrow will travel (7) many cubits, and you know that in such a case the bow itself has done nothing to propel the arrow.