Researches on Explosives. 205 



June 21, 1894. 

 The LORD KELVIN", D.C.L., LL.D., President, in the Chair. 



Dr. John Rose Bradford and Professor M. J. M.'Hill were admitted 

 into the Society. 



A List of the Presents received was laid on the table, and thanks 

 ordered for them. 



The following Papers were read : 



I. " Researches on Explosives. Preliminary Note." By Captain 

 Sir A. NOBLE, K.C.B., F.R.S., M.I.C.E., &c. Received June 

 13, 1894. 



The researches on which I, in conjunction with Sir F. Abel, have 

 been engaged for very many years, have had their scope so altered 

 and extended by the rapid advances which have been made in the 

 science of explosives, that we have been unable to lay before the 

 Society the results of the many hundreds of experiments under 

 varied conditions which I have carried out. We are desirous also 

 of clearing up some difficulties which have presented themselves 

 with certain modern explosives when dealing with high densities 

 and pressures, but the necessary investigations have occupied so 

 much time that I am induced to lay a few of our results before the 

 Society, trusting, however, that before long we may be able to submit 

 a more complete memoir. 



A portion of our researches includes investigations into the trans- 

 formation and ballistic properties of powders varying greatly in 

 composition, but of which potassium nitrate is the chief constituent. 

 In this preliminary note I propose to refer to powders of this descrip- 

 tion chiefly for purposes of comparison, and shall devote my 

 attention principally to gun-cotton and to those modern explosives 

 of which gun-cotton forms a principal ingredient. 



In determining the transformation experienced during explosion, 

 the same arrangements for firing the explosive and collecting the 

 gases were followed as are described in our earlier researches,* and 

 the gases themselves were, after being sealed, analysed either under 

 the personal superintendence of Sir F. Abel, or of Professor Dewar, 



* ( Phil. Trans.,' rol. 165, p. 61. 



