24 pr. and 9 pr. These were constructed of iron with a wooden head, fitted metal plug at the base with three vents, a tail piece or flange continuing from the base so as to enclose half the periphery of each jet. This arrangement imparts a rotary motion to the rocket.
In 1853 Macintosh patented a method of rotating the tube from which the rocket was fired so as to give an initial rotary movement before the flight commences.
The following year Fitzmaurice patented the idea of causing rotation by a screw-shaped head, and Court a method by which the fire impinged on surfaces inclined to the axis of the rocket.
In 1826 Congreve patented a method of fixing two or more rockets together so that the heading of one ignited the next and so obtained a longer time of burning; this method is, however, again anticipated in Frézier's book.
About this time all the leading Powers in Europe were manufacturing rockets for war purposes, factories for their manufacture being established at Warsaw, Turin, Toulon, and Metz. The Russians used them at this period in their war with Turkey, firing them in salvoes of nine.
In 1831 a series of trials were made by the Swiss military authorities of 6 lb. rockets fired from a 6 ft. tube, when a range of from 18-1900 yards was obtained, and three hits registered out of five were made at 1,100 yards.
Although great interest was aroused by the rocket for war purposes, it quickly subsided, and it is now practically only used for signalling and line-carrying purposes.
William Bourne, who describes himself as a "poor gunner," the first to produce an original book on artillery m this country, as distinct from translation of continental works, makes the following observations on military pyrotechnics: "Divers gunners and other men have devised sundry sorts of
