Put these two pieces aside, and next saw a length of stripwood, ½" × ½" × 5"; saw a slit about ¼ inch from one end and hammer it on the metal top of a bottle of Le Page's liquid glue as in Fig. 329. The corner a should be cut or filed off. A small screw-eye is screwed into the wood just below the metal top. Saw a piece of stripwood, ½" × ¼" × 3½", tie this firmly with elastic to the other end of the first piece of stripwood as in Fig. 330. This elastic constitutes the propulsive force. The ancients used catgut, which formed a thick coil, stretched from H to K, the lever passing through the middle of the coil. The pulling down of the lever gave additional twist to the coil, which reacted strongly on release. Now fasten the sides a b c d and A B C D together by nailing and glueing them to two pieces of stripwood, ½" × ½" × 2¼". Then glue H K securely into the slots G so that the beam with the stone-holder M is upright. Push a round stick through the holes F, for a windlass; this can have holes drilled in the portions that project, to hold sticks for turning the rod. A piece of thread is tied to the screw-eye Q, and wound round the windlass F; when this thread is tightened the beam is pulled down, then when let go it flies up, causing anything placed in the tin, M, to be shot some distance. The safest 'stones' to put in this pan are pieces of cork or small pieces of wood. The following additions can be made to the model:
(1) RR are pieces of stripwood, ½" × ¼" × 4", glued to the sides and carrying a strip, T. This strip T in the olden days was covered with leather and was so placed that the beam carrying the stone-holder would abut against it. Notice the struts W for supporting the posts R.
(2) N O is a rod (about ¼ inch in diameter) passing through two small screw-eyes fixed in a piece of stripwood, S, ½" × ¼" × 3¼". A piece of strong wire, P, passes through hole in rod N O; it is bent so that it cannot work out, and the other end is bent to just catch the holder, M, when it is pulled down. A releasing handle is fastened to the rod, N O at O. The beam S is glued into slots in A B C D and a b c d, so that when the beam is pulled down the catch P clutches M.
(3) Small screw-eyes may be screwed in at A, a, B, b, for holding ropes to fasten the machine to pegs in the ground. Rollers may also be made to fit under C and E.
This toy is an attractive one, because it really works successfully. It must be strongly put together, for the beam when pulled down flies up with considerable force.
Stone-throwers like this were used at the siege of Acre. Very often these engines had special names given to them. For example Philip of France had a very good engine of war called 'The Bad Neighbour,' and inside Acre the Turks had one called 'The Bad Kinsman.'
Cannons of the Fourteenth Century. These are very easily made. Figs. 331 and 332 show two that can be copied.
In Fig. 331 a piece of wood is cut to the shape of A B; a groove is then filed in it, into which the cannon C is glued. The cannon may be made of a roll of brown paper (two pieces may be pasted together for greater strength) with four bands of cartridge paper painted yellow and gummed round it, or it may be a piece of wood filed to shape and circled with bands of lead.
Fig. 331
Fig. 332