A summary of the history, construction and effects in warfare of the projectile-throwing engines of the ancients, with a treatise on the structure, power and management of Turkish and other Oriental bows of mediæval and later times

by Sir Ralph Payne-Gallwey

H. The loop which is hitched over the iron pin at the top of the arm when the stone is in position in the sling, as shown at A and B, [fig. 7].]

Fig. 8.—Catapult (with a Sling). Surface view of frame and mechanism. Scale: ½ in. = 1 foot. The arm EE is here shown wound down to its full extent. (Compare with B, [fig. 7], page 14.)

I.	I.	}	The side-pieces.
II.	II.	}
III.	IV.		The large cross-pieces.
	V.		The small cross-piece.

The ends of the cross-piece beams are stepped into the side-pieces.

AA. The skein of twisted cord.

BB. The large winding wheels. The skein is stretched between these wheels, its ends passing through the sides of the frame, and then through the wheels and over their cross-bars. ([Fig. 12], p. 19.)

By turning with a long spanner ([fig. 6], p. 12) the squared ends of the spindles DD, the pinion wheels CC rotate the large wheels BB and cause the latter to twist the skein AA, between the halves of which the arm EE is placed.

FF. The wooden roller which winds down the arm EE. ([Fig. 6], p. 12.)

The roller is revolved by four men (two on each side of the engine) who fit long spanners on the squared ends of the iron spindle GG.