Ruggieri, under this head, describes a method of illuminating by impregnating wick similar to that used for matchmaking, with a mixture of sulphur, antimony, and saltpetre. This was wired on to a metal framework. He says it is better than lancework for outlining curves, volutes, etc., as the line is continuous. This difficulty is disposed of in modern English lancework by the closer spacing of lances on curves rendered possible by the smaller lances now used. He also remarks that this method was rarely used in his time and it is now quite discontinued. Another device of which he seems proud was a palm tree, the leaves of which were of thin metal from which project spikes upon which was hung cotton impregnated with a composition composed of “vert-de-gris, vitriol blue and sel ammoniac” (copper acetate, copper sulphate and ammonium chloride). Immediately before firing the cotton was soaked with alcohol. Actually this composition can hardly be considered pyrotechnic; what takes place is that the alcohol burns, and the flame thus created is coloured with the copper present in the salts. The whole arrangement is too cumbersome and involved for modern use, but at the time of its inception, when colour was practically unknown, no doubt it attracted great admiration. CHAPTER VI COMPOUND FIREWORKS (_continued_) Ruggieri’s next class (fireworks turning vertically) includes the following: 1. Revolving Suns. These are merely vertical wheels; he appears to use this term for the more ambitious pieces of this kind. 2. Vertical Wheels. He illustrates a vertical wheel exactly as made to-day under that name. It has, however, been elaborated by the addition of colour cases on the spokes and centre, as rosette and rainbow wheels; also by the application of saxons to the spokes, as saxon wheels. He also shows the triangle wheel, consisting of three spokes with grooved ends to receive the cases whose sides form the sides of an equilateral triangle. This has been further developed into the double triangle wheel, with two sets of spokes placed one set behind the other. In all the wheels in this class the cases fire in succession, not as in the case of the sun—simultaneously. Windmills he illustrates as flat bars pivoted in the centre with three cases at either end fired in succession. There also were three, four, and up to eight-armed windmills of the same kind. The nearest device to these of modern times is the chromatrope, the simplest form of which has two bars with a gerb at either end so set as to revolve them in opposite directions, the front one carrying two saxons. This piece, which is of comparatively simple design, gives an extraordinarily fine effect by the intersections of the various streams of fire.