Sky-rockets
Rockets being of the fire-works most in use, we shall give them the
preference in description. As the performance of rockets depends much
upon their moulds, they should be made according to the following
proportions:--Taking the diameter of the orifice, its height should be
equal to six diameters and two-thirds: the choke, one diameter and
one-third of this model, will serve for every rocket from 4 oz. to 6
lb.--For instance:--suppose the diameter of a rocket of 1 lb. be 1-1/2
inch, then its length being 6 diameters and two-thirds, the length of
the case must be 10-1/3 inches, and the choke 2-1/4 inches. Your
rammer must have a collar of brass, to prevent the wood from
splitting.