The next thing required, is a piece of hooping, or curved stick, about 6⁄8 of an inch broad, and as long as the case, 71⁄4 inches. In the centre of this, bore a hole, and countersink it; then, with a screw, an inch and a quarter long, screw the hooping, at right angles, on the bottom of the case, through the point s of fig. 45, which must be enlarged to receive the screw. A touch of glue may still farther hold the wood in position. It will now assume the shape of a cross, like figs. 50 and 51. Fig. 50 shows the under side of the case; fig. 51 the upper. From w to x lead a bit of naked match; push the ends into both holes, and secure with a little wetted meal, pressed in with a knife. Do the same with y and z. Paste a piece of double-crown, 3⁄4 of an inch broad, and of sufficient length, and cover each of the two pieces of match, with two layers of the paper. Turn it over, like to fig. 51; connect the holes a and b with a bit of naked match; and, under the centre of it, slip another piece of naked match, having a piece of touch-paper round the protruding end: cover the match with two thicknesses of pasted paper, in the same manner as the under holes. The tourbillion is now complete. See that it will balance, and swing round easily, when laid upon a level surface. The proper way to fire it, is from a flat sheet of iron, or a flagstone. Light the touch paper; the fire will communicate to the side holes, and set it in rotation. As soon as 1⁄8 of an inch of fuse has burnt from each end, and the piece has got well into action, the 4 under holes will catch, and cause it to ascend.
Instead of this mode of making a tourbillion, some charge it with an inch of solidly rammed clay, in the middle; fasten the stick, by crossing it with binding-wire; bore a hole through the middle of it, and of the clay, and slip it over a tapering-wire, standing upright in a block, like the spindle of a rocket. Four holes only are then used; two of rotation, and two of ascension; and the whole are fired at once, the match starting from one of the under holes, going to the side hole; over, across, to the other side hole, and on to the other under hole.
Instead of making them with clay in the middle, there is yet a better method of having two cases, each about 4 inches long; and gluing, or fastening them with tin-tacks on a centre-piece, turned with a tenon at each end, fig. 52; two balancing arms, one on each side, must then be fixed to the centre-piece.
In a windmill, as is well known, the vanes, or sails, are set at an angle. There is a toy, made of two slips of tin, forming a cross, and set at an angle, sloping upwards, called the flying dutchman; this, when spun with a string, from a handle like a humming-top, flies up into the air, on escaping from the string. Steel Fliers, with two vanes, are used by sportsmen to practise shooting flying. Small balloons, some years ago, in a room in the Polytechnic Institution, free from a current of air, were guided or driven by a similar contrivance, moved by clockwork. The screw-propeller of a ship acts on the same principle. I think it possible that, if two vanes were fixed in the central piece of wood, set at an upward angle of 10, 15, or 20 degrees from the horizontal, they might assist the ascension, and so cause the tourbillion to reach a greater height; or, the vanes alone might cause it to rise, upon 4 side holes, two to the left, and two to the right, causing it to rotate. The design is shown at fig. 54, the shape of the vane at fig. 53. I have not yet tried it, so offer it only as a suggestion.
FOOTNOTES:
[A] Tourbillion, from tourbillon, like postillion, from postillon, the i being inserted to approximate the pronunciation of the French. In pavilion, from pavillon, and vermilion, from vermillon, one l is dropped; so in battalion, from bataillon; while medallion, from medaillon, retains the ll.
[SAXONS.]
These are unchoked cases, charged like a tourbillion, but pierced only with holes of rotation, for the purpose of turning a coloured fire. Drive them in a mould, as directed before. A good size is, 5⁄8 internal, 7⁄8 external, 6 or 7 inches long. Let the tenon enter the case 3⁄8 of an inch: charge the composition firm till within 1⁄2 an inch of the top, which leave vacant. Remove it, and fill the 3⁄8 occupied by the tenon, with plaster of paris. Have a centre-piece, turned like fig. 55, with a tenon, 5⁄8 diameter at each end, 1⁄2 an inch long. Glue a case on each tenon. Let the centre-piece be 6 inches long, exclusive of the tenons; so, if the saxon cases are 7 inches long, each, the entire length, as fig. 56, will be 20 inches. Make a hole at a, and another at c, with a shielded bradawl, 3⁄16 of an inch diameter. Put a bit of naked match in the hole a, carry it round x and y, along to c and on to z. It must be pushed into c with a blunt wire. Cover it with two thicknesses of pasted paper, like the tourbillion. Leave the match exposed at x, y, and at z, and brush it over with meal paste. If the central piece of wood were now put on a horizontal spindle, and fire communicated to the match z, the holes a and c would cause it to rotate, and produce a white circle of fire. This, however, would be hardly worth making; but, by fixing at b, a little case of coloured fire, a splendid effect is produced. This case of colour is usually tied to a nail, driven in at b; but a little tenon of wood may be glued there instead, and the case of colour must be then charged, with a vacancy at the bottom, to fit on the tenon. The case of colour must be timed to burn as long as the saxon; rather more than an inch will be sufficient.
Saxons are sometimes made by charging a roman candle case with an inch of clay in the middle, and boring a hole through the clay, to receive a spindle. Only one half of the case burns at a time; a leader, placed at the bottom, near the central clay, conveys the fire to the other end; and continues the rotation. For distinction, they are called Chinese fliers.