Gunpowder half-a-pound, salt-petre fifteen pounds, sulphur two pounds, charcoal six pounds.
For Rockets of the largest size:—
To eight pounds of salt-petre, add twenty ounces of sulphur, and forty-four ounces of charcoal.
The several ingredients should be each ground separately, and sifted, and afterwards weighed and mixed together, in readiness for loading the cartridges
We now proceed to describe some of the various modifications which Rockets are susceptible of in their exhibitions; in which we shall endeavour to blend the most prominent features: were we to attempt to give the whole, it would annihilate the purpose of our work; indeed it is impossible to set limits to the field of variety which here opens itself; we shall therefore describe a few of the most particular, and leave the rest to the Tyro, assuring him it will afford a pleasing source of amusement, and furnish excellent matter for the exercise of his ingenuity.
To cause a Rocket to ascend in a spiral form.
1. TO CAUSE A ROCKET TO ASCEND IN A SPIRAL FORM.
The rod of a Rocket has been compared to the rudder of a ship, or tail of a bird; the purpose of which is to make the ship or bird turn towards that side to which it is inclined; a straight rod, as experience proves, causes a Rocket to ascend in a straight line, because the centre of gravity lays in, or is parallel to the centre line of the rod; but if we apply a crooked rod, or one that forms part of a circle, this will not be the case, for the first effect will be to make the Rocket incline towards that side to which it is bent; but the centre of gravity bringing it afterwards into a vertical position the result will be, that the Rocket will ascend in a spiral form.
Rockets exhibited in this way, evidently displace a greater volume of air, therefore as a consequence they cannot ascend so high as those that are impelled in a straight direction; but, nevertheless, their peculiar flight will produce a very pleasing effect.