344 
ME. F. A. ABEL’S CONTRIBUTIONS TO 
distended into thin sheets at each end by the detonations. The experiments with tubes 
made of different materials were extended during the progress of this investigation, 
when silver fulminate was used ; the above results, in addition to those obtained with 
iron tubes differing in strength, indicated, however, that the transmission of detonation 
is regulated to an important extent, in experiments of some magnitude, by the strength 
of material composing the tube and the consequent resistance which it opposes locally 
to the force developed by the initiative detonation. 
The almost instantaneous manner in which the detonation appeared to be transmitted 
from the point of first explosion to the distant mass of gun-cotton, through the medium 
of tubes, led me to believe that the mechanical condition of the gun-cotton might, 
under these circumstances, be without effect upon the results obtained. If gun-cotton 
yarn or wool be struck with a hammer upon an anvil, unless the layer interposed 
between the support and striking body be very thin, repeated blows are required to 
accomplish the detonation of any part of it, as the force is mainly expended, in the 
first instance, in imparting motion to the particles of the mass, which becomes com- 
pressed, and thus reduced to a condition in which the particles offer great resistance to 
mechanical motion before the force applied can develop chemical metamorphosis. 
For the same reason*, if a fuse charged with mercuric fulminate, to an extent greatly 
in excess of that required to detonate a mass of compressed gun-cotton, be exploded in 
the centre of a mass of gun-cotton yarn or wool, freely exposed, or even if a small disk 
of compressed gun-cotton be detonated in contact with the loose material, the latter 
will not be detonated, but be simply dispersed in small fragments, with or without 
inflammation, because the particles of the wool or yarn are not in a condition to oppose 
resistance to the force applied, which therefore is expended in imparting motion to 
them. It can be conceived, however, that the blow, or gas-wave, to which a mass 
composed even of quite loose fibres is opposed may be so sudden in its operation that 
the particles which it first encounters undergo chemical disintegration before time can 
operate in causing the force to expend itself in imparting mechanical motion to the 
mass. In some experiments to be presently described, this action of a sudden blow 
upon those particles of a compressed mass of gun-cotton (placed so as to be perfectly 
free to move) which it first encounters will be found conclusively demonstrated (p. 361) ; 
but the same kind of action of the gas-wave upon a mass of uncompressed gun-cotton 
fibre was strikingly illustrated by one or two experiments with wrought-iron tubes of 
the kind described. 
In the first instance, a loosely twisted thread or yarn of gun-cotton was wound pretty 
firmly into a ball of such size as to fit rather tightly into one extremity of a tube 
T25 inch in diameter and 2 feet ('608 m.) long. The detonation of a 1-ounce (3T2 
grms.) disk of gun-cotton in the opposite extremity of the tube induced the detonation 
of the ball of yarn. Had the latter been in close contact with the detonated disk, 
freely exposed, it would simply have been scattered, some particles being probably 
* Philosophical Transactions, 1869, vol. clix. pp. 497, 498, 501. 
