The Probert Encyclopaedia of Warfare

SLING

A sling is a primitive projectile weapon comprising a short piece of leather to each end of which cords are attached. A stone is placed in the pocket formed by the leather, and, gripping both cords, the slinger whirls it. When he lets one cord free the stone is thrown out by the momentum. The sling is frequently referred to in Biblical history, and in classical times the Balearic islanders were renowned slingers.
Research Sling