THE EOYAIi AETILLBEY INSTITUTION. 
119 
EXPERIMENTS TO DETERMINE THE COMPARATIVE LIA¬ 
BILITY OF COPPER, ORDINARY BRONZE (“ GUN-METAL”), 
AND PHOSPHOR-BRONZE TO EMIT SPARKS WHEN SUB¬ 
JECTED TO SHARP FRICTION OR PERCUSSION. 
BY 
MAJOE V. D. MAJENDIE, E.A. 
H.M.’S INSPECTOR OP GUNPOWDER WORKS. 
The experiments were carried out in one of the workshops of the 
Royal Gunpowder Factory, Waltham Abbey, after dark on the evening 
of the 26th October, 1874, in the presence of Colonel Younghusband, 
Major Majendie, Major Morgan, and others. 
During each experiment the gas was extinguished, leaving the room 
in total darkness, so that the least spark could be readily distinguished. 
The numerals distinguishing the different samples of phosphor-bronze 
experimented with, indicate different alloys, No. 2 being the softest 
and No. 8 the hardest. 
The results are recorded exactly as they were noted down after, each 
experiment. 
The results obtained show that copper, gun-metal, and phosphor- 
bronze are all liable to emit sparks, or, as it is commonly called, “ strike 
fire/ ; when subjected to a certain description and degree of friction, the 
degree of liability appearing to vary with the different alloys and 
frictional surfaces, and, to some extent, with the construction and con¬ 
sequent rigidity of the article employed. So far as they went, these 
experiments appeared to indicate that the harder descriptions of 
phosphor-bronze emit sparks less readily than the softer samples, and 
less readily than ordinary bronze or even than copper. 
The negative results obtained in series B and 0 can hardly be safely 
accepted as conclusively establishing the absolute non-liability of the 
various metals employed to “ strike fire ;; under the conditions described. 
With a slight variation of those conditions it is not impossible that 
sparks would be obtained. 
The real value of these experiments consists in the positive evidence 
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