Page:Pyrotechnics the history and art of firework making (1922).djvu/221

 consisted of a solid wheel round which are a series of mines which discharged in succession as each turning case lit. The second was similar but more elaborate, having rockets as well as mines, and was a variation of the rocket wheel.

In his description of the Girandole, he explains that it is composed of two horizontal wheels one above the other. This is the form taken by the rocket wheel as fired in this country which, as we have seen, was known as the girandole wheel. Ruggieri, however, appears not to have used rockets on his girandole.

The last device he mentions in this class is the Spirali, which consisted of a framework in the form of a cone, round which was wound a spiral of cane fitted with lances.

A very effective piece, not mentioned by Ruggieri, is the revolving fountain; it consists of a wood centre bored to turn on a vertical spindle. The centre has two spokes fitted with gerbs for turning, and has playing vertically a large gerb and Roman candles. The turning gerbs play tangentially and slightly upwards.

Jones describes a similar device under the name of "illuminated spiral wheel"; also two other horizontal pieces—the spirali and the plural wheels, which approximate to the furiloni and caprice wheels of the present day.

The spiral and helix are much used in larger devices, and the use of modern lancework and colour has greatly added to their effect.

Ruggieri's next division deals with built-up lancework pieces such as the globe, which it was thought worthy of separate mention in his time, but to-day is included with many devices of this nature too numerous to mention, forming, as they do, a large proportion of the mechanical and other pieces used in display work.

He then deals with tourbillions and table wheels. The