408 Capt. Noble and Mr. F. A. Abel [June ]8, 



IX. " Researches on Explosives. Fired Gunpowder/' By Capt. 

 NOBLE, late Royal Artillery, F.R.S., F.R.A.S., F.C.S., and 

 F. A. ABEL, F.R.S., Treas. C.S.* 



(Abstract.) 



After an historical review of the investigations and theoretical views 

 relating to the results produced upon the explosion of gunpowder, which 

 have been published during the last 150 years, the authors proceed to 

 describe the chief objects contemplated by their researches, which are in 

 continuation of some commenced by Captain Noble in 1868, and de- 

 scribed in a lecture delivered at the Royal Institution in 1871. 



These objects were as follow : 



First. To ascertain the products of combustion of gunpowder, fired 

 under circumstances similar to those which exist when it is exploded in 

 guns or mines. 



Second. To ascertain the tension of the products of combustion at the 

 moment of explosion, and to determine the law according to which the 

 tension varies with the gravimetric density of the powder. 



Third. To ascertain whether any, and, if so, what well-defined variation 

 in the nature or proportions of the products accompanies a change in the 

 density or size of grains of the powder. 



Fourth. To determine whether any, and, if so, what influence is exerted 

 on the nature of the metamorphosis by the pressure under which the gun- 

 powder is fired. 



Fifth. To determine the volume of permanent gas liberated by the 

 explosion. 



Sixth. To compare the explosion of gunpowder fired in a close 

 vessel with that of similar gunpowder when fired in the bore of a gun. 



Seventh. To determine the heat generated by the combustion of gun- 

 powder, and thence to deduce the temperature at the instant of ex- 

 plosion. 



Eighth. To determine the work which gunpowder is capable of per- 

 forming on a shot in the bore of a gun, and thence to ascertain the total 

 theoretical work, if the bore be supposed of indefinite length. 



The several methods of experiment adopted by the authors, and the 

 most important apparatus employed in their researches, are next described 

 in detail. The experimental operations include : 1 . Measurement of 

 pressure developed ; 2. Measurement of volume of permanent gases ; 

 3. Measurement of heat developed ; 4. Collection of gases; 5. Collection 

 of solids ; 6. Analysis of the gaseous and solid products. 



* We have to express our acknowledgments of the valuable assistance we have 

 received from Mr. Charles Hutchinson in making the very laborious calculations, from 

 Mr. George Stuart in the mechanical arrangements and in carrying out the experiments 

 themselves, and from Dr. Kellner and Messrs. Bearing, Dodd, and Hobler in the ana- 

 lytical portion of these researches. 



