THE HISTORY OF EXPLOSIVE AGENTS. 
357 
III.— CONCLUSIONS REGARDING THE TRANSMISSION OF DETONATION BY TUBES. 
The results which have been described on the transmission of detonation by tubes 
appear to have established the following points : — 
1. The distance to which detonation may be transmitted through the agency of a tube 
to a distinct mass of explosive substance is regulated by the following conditions : — 
(a) By the nature and the quantity of the substance employed as the initiative deto- 
nator, and by the nature of the substance to be detonated, but not by the quantity of 
the latter, nor by the mechanical condition in which it is exposed to the action of the 
detonation. 
(b) By the relation which the diameter of the “detonator,” and of the charge to be 
detonated bear to the diameter of the tube employed. 
(c) By the strength of the material composing the tube, and the consequent resist- 
ance Avhich it offers to the lateral transmission of the force developed at the instant that 
detonation is produced. This condition does not appear to affect appreciably the results 
produced by detonation on a small scale, but its influence becomes apparent in larger 
operations. 
(d) By the degree of roughness of the tube employed for transmitting detonation, 
or, in other words, by the amount of resistance opposed to the gas-wave and the amount 
of force consequently expended in overcoming the friction between the gas and the sides 
of the tube, or other impediments introduced into the latter. 
( e ) By the degree of completeness of the channel, and by the positions assigned to 
the “ detonator ” and the charge to be detonated. It need scarcely be pointed out that 
if the tube be fissured, or much enlarged either at the seat of detonation or at any other 
part (e. g. if injured by the effects of a previous detonation), or if even a very slight 
break in continuity exists in the tube, the extent to which force is transmitted must 
be proportionately diminished. It is also obvious that if the detonator, or the charge 
to be detonated, be placed against the opening of the tube instead of being inserted 
into the extremity, the conditions are comparatively unfavourable to the development 
of detonation by transmission ; on the other hand, if the detonator be introduced some 
distance into the tube instead of being simply inserted into one opening, the loss of 
force by lateral dispersion is considerably reduced, if not altogether obviated, and the 
gas-wave consequently retains detonative power at an increased distance from the 
starting-point. 
2. The nature (apart from strength or power to resist opening up or disintegration) 
of the material composing the tube through which detonation is transmitted generally 
appears to exert no important influence upon the result obtained, so far as could be 
determined by the experiments described. At any rate the effects produced by differ- 
ences with respect to smoothness of the interior of the tubes far outweigh those which 
may prove to be traceable to differences in the nature of material of which the tubes 
consist. 
