The Chemistry of Powder and Explosives - Sciencemadness Dot Org

LANCES 69
minute with an illumination of 22,000 candlepower. The red light
was made from 24 parts of strontium nitrate, 6 of flake aluminum,
and 6 of sulfur with a shellac binder and burned for 1 minute
with an illumination of 12,000 to 15,000 candlepower. The compositions
were loaded into the cases by means of a pneumatic
press, and filled them to within 5/16 inch of the top. The charge
was then covered with a Vg-inch layer of starting fire or first fire
composition, made from saltpeter 6 parts, sulfur 4, and charcoal
1, dampened with a solution of shellac in alcohol, and this, when
the device was used, was fired by an electric squib.
Lances
Lances are paper tubes, generally thin and of light construction,
say, y± to % inch in diameter and 2 to 3 ] /2 inches long,
filled with colored fire composition, loaded by tamping, not by
ramming, and are used in set pieces, attached to wooden frameworks,
to outline the figure of a temple or palace, to represent a
flag, to spell words, etc. When set up, they are connected by
quickmatch (black match in a paper tube) and are thus lighted
as nearly simultaneously as may be. They are often charged in
such manner as to burn with a succession of color, in which
event the order of loading the various colors becomes important.
Green should not be next to white, for there is not sufficient contrast.
And green should not burn after red, for the color of the
barium flame appears to one who has been watching the flame of
strontium to be a light and uninteresting blue. The order of
loading (the reverse of the order of burning) is generally white,
blue (or yellow or violet, green, red, white. In the tables on page
70 a number of lance compositions are listed, illustrative of
the various types and corresponding to considerable differences in
cost of manufacture.
Picrate Compositions
Ammonium picrate is used in the so-called indoor fireworks
which burn with but little smoke and without the production of
objectionable odor. On page 71 some of the compositions recommended
by Tessier 24 for Bengal lights are tabulated.
24 Op. cit., second edition, pp. 383-396.