Great Bhurtpoor Gun, stationed at Woolwich. 183 



4. Under the left trunnion, the weight of the powder-charge 

 and of the projectile to be used : "According to the weights of 

 the Shah Jehan : the Ball 30 Sirs, powpler 10 Sirs." (The 

 sir, a weight established by the Emperor Shah Jehan and still 

 used in Hindustan, is equal to 2 Jbs.. avoirdupois*.) 



A belief has been hitherto entertained that the metal of this gun 

 contained a proportion of gold, and silver, in consequence of an 

 existing tradition that it was the custom of the high dignitaries 

 to throw articles of gold and silver into the metal at the time of 

 casting. The results of analysis have demonstrated the erro- 

 neous nature of this tradition, at any rate as applied to this 

 particular instance, as no trace of the precious metals was 

 discovered in the specimens of the gun examined. 



Three specimens of the metal composing the gun have been 

 submitted to quantitative analysis, — one sample having been 

 taken from near the muzzle, a second from between the trun- 

 nions, and the third from the breech. The means of the 

 analytical results obtained show that — 



1. The metal of which the main casting itself consists is 

 composed of lead, tin, and copper; and the proportions in 

 which these metals have been employed vary to a very marked 

 extent in different parts of the gun. The alloy composing the 

 portion near the trunnions contains considerably less lead, and 

 larger proportions of copper and tin, and is therefore compara- 

 tively harder and more tenacious, than that forming the front 

 portion, or chase of the gun. 



2. The mass of metal enclosing or forming the exterior of the 

 breech of the gun consists of an alloy of copper and zinc, resem- 

 bling ordinary brass in its composition,, and containing small 

 quantities of iron, lead, and tin, which probably existed as acci- 

 dental impurities in the metals used. These results confirm the 

 conclusion above arrived at, that the exterior of the breech con- 

 sists of a distinct casting. 



The per-centage results obtained by the analysis of the speci- 

 mens above referred to are as follows : — 



Composition of the metal near the 



Copper . 

 Tin . . 

 Lead . . 

 Arsenic . 

 Antimony 



Trunnions. 



Muzzle. 



86-10 



8173 



464 



3-33 



9-12 



1510 



015 



trace 



trace 



trace 



Mallet, ■ On the Construction of Artillery.' 



