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FRAGMENTS OF SCIENCE 



tlie earliest Woolwich experiments. It liad been a widely 

 spread opinion among artillerists, tliat a bronze gun pro- 

 duces a specially loud report. 1 doubted from the outset 

 whether this would help us; and, in a letter dated 22d 

 April, 1874, I ventured to express myself thus: ''The 

 report of a gun, as affecting an observer close at hand, is 

 made up of two factors — the sound due to the shock of the 

 air by the violently expanding gas, and the sound derived 

 from the vibrations of the gun, which, to some extent^ 



Fig. 6.— Breech-loading Fog-signal Gun, with Bell Mouth, ^ proposed by 

 Major Maitland, R. A,, Assistant Superintendent. 



rings like a bell. This latter, I apprehend, will disappear 

 at considerable distances." The result of subsequent trial, 

 as reported by General Campbell, is, "that the sonorous 

 qualities of bronze are greatly superior to those of cast-iron 

 at short distances, but that the advantage lies with the baser 

 metal at long ranges. '* ' 



* The carriage of this gun has been modified in construction since this 

 drawing was made. 



* General Campbell assigns a true cause for this difference. The ring of the 



