II. Saltpetre three pound and a half, sulphur two pound and a half,
meal powder one pound, antimony half a pound, glass dust four ounces,
brass dust one ounce.
N. B. These compositions, driven one inch and a quarter in a one ounce
case, will burn one minute, which is much longer time than an equal
quantity of any composition will last, that has yet been made public.
For Amber Lights.
Meal powder nine ounces, and amber three ounces. This charge may be
drove in small cases, for illuminations.
For Lights of another Sort.
Saltpetre three pound, brimstone one pound, meal powder one pound,
antimony ten ounces and a half. All these ingredients must be mixed
with the oil of spike.
For a Red Fire.
Meal powder three pound, charcoal twelve ounces, and saw dust eight
ounces.
For a Common Fire.
Saltpetre three pound, charcoal ten ounces, and brimstone two ounces.
To make an Artificial Earthquake.
Mix the following ingredients to a paste with water, and then bury it
in the ground, and in a few hours the earth will break and open in
several places. The composition: Sulphur four pound, and steel dust
four pound.
Having laid down, under the preceding heads, the different
compositions used in fireworks by our modern artists; I shall, in the
next place, give some tables of charges that were formerly used,
according to the several accounts given by those authors from whom
they are collected: but if the reader will consider, he will find the
charges in these tables to be very uncertain, by comparing their
method of determining the size and weight of rockets, and the
proportions of ingredients thereto, with the method taught in this
work, which is so plain, easy, and certain, that I have never yet
known it fail; and doubt not, but that it will be so allowed by all
who chuse to make a tryal thereof.
The subsequent table is taken from Siemienowicz, wherein is specified
the different charges of sky rockets, from half an ounce to one
hundred pound; the charges being calculated in proportion to the
weight of a leaden ball of the same diameter as the bore of each
mould; which bores are divided into inches and lines[1], and each line
into twelve equal parts, according to the French method.