The Chemistry of Powder and Explosives - Sciencemadness Dot Org

96 PYROTECHNICS
pastilles turn conveniently, care is taken not to load more of
it than a length of 15 mm. in the tube." 37
Nos. 126, 128, and 129 are also for ordinary pastilles. No. 126
"has not much force; it is incapable alone of making a pastille
turn with the necessary rapidity. Hence care is taken in charging
it to introduce only a small quantity into the tube." It bums
with a white flame "forming a crown, more or less lacy-edged,
from which rays and sparks are thrown out." 38
The two compositions, Nos. 142 and 126, evidently burn while
the pastille is turning from the initial twirl given it by the hand.
When the fire reaches the next composition, No. 128, the pastille
accelerates by its own power. This gives "reddish rays, very
straight and very numerous," and No. 129 gives "a white flame
around the disc, and numerous and persistent sparks which fall
down forming a sort of cascade on each side of the pastille." 39
Neither No. 128 nor 129 is bright enough to make much of
a show if the colored fire is also burning. When they bum to an
end, the fire is communicated to the colored composition; at the
same time the bright diamond composition, either No. 149 or 152,
commences to burn. No. 149 produces "a splendid aureole of
silver-white flowers. These flowers are less developed than those
produced by steel wool and make a different effect from the
latter." 40 No. 152 produces a "splendid effect—no inflamed disc,
no reddish sparks—numerous jasmine flowers of all dimensions
forming a vast aureole of a striking white." 41
Plumbic powder No. 1 is made from lead nitrate 12 parts,
potassium nitrate 2 parts, and black alder charcoal 3 parts. 42
The materials are powdered and mixed, and then rolled in a
wooden ball-mill with balls of hard lead (Pb 5, Sb 1) or brass or
bronze.
Tessier 43 gives credit to the earlier French pyrotechnist, Chertier,
for the introduction into pyrotechny of lead nitrate (which
had been used before his time only for the preparation of slow-
87 Ibid., p. 408.
88 Ibid., p. 403.
39 Ibid., p. 404.
*°Ibid., p. 411.
41 Ibid., p. 412.
i2 Ibid., p. 281.
43 Op. cit., p. 118.