Page:Pyrotechnics the history and art of firework making (1922).djvu/147

 Chlorate of potash, from the introduction of which into pyrotechny modern effects and colours may be said to date, has at the same time been responsible for many accidents. As will be seen in the later chapters on firework compositions, for many years chlorate of potash and sulphur were used freely in the same mixtures, and many as were the accidents caused by so doing, yet it is incredible that they were not far more numerous.

Most makers were well aware of the dangerous nature of this admixture, but persisted in using it, as the colours so obtained were at that time unapproached by other means; naturally no manufacturer wished to be alone in the discontinuance of some of the most striking effects at the time available, or to give competition the consequent advantage.

In August, 1893, a man was fatally burned whilst simply emptying a small quantity of crimson stars from one tray to another; the slight friction so caused was sufficient to ignite the stars and thus fire the whole contents of the building. This unfortunate accident took place at the works of C. T. Brock and Co., then at South Norwood, and seems even more unfortunate when one learns that with the exception of this particular crimson, they had practically eliminated chlorate and sulphur colours.

The following year, by Order in Council No. 15, the admixture of chlorate of potash and sulphur was made illegal.

Previous to this accident, during the same year and in the same works, a serious accident involving the death of one workman and the injury of another, was caused by a barrel of chlorate of potash being delivered and marked nitrate of potash (saltpetre). Its use in a composition containing sulphide of arsenic (orpiment) produced a mixture approximately to that used in some fog signals and designed to fire by percussion. The natural effect was the serious explosion that followed.