THE HISTOEY OE EXPLOSIVE AGENTS. 
343 
into one extremity ; its detonation did not induce that of a disk of the same diameter 
inserted into the other extremity of the tube ; whereas the detonation was effected by 
the explosion of only 1 ounce (3T2 grins.) in the further extremity of a tube the 
same length and substance, but only 1-25 inch (-031 m.) in diameter. With a tube of 
the larger diameter (1'75 inch) and 2 feet 3 inches (‘684 m.) long, the detonation of 
2 ounces of gun-cotton of the above diameter in one extremity induced partial deto- 
nation in the other extremity. In these experiments the diameter of the tubes was 
0-75 inch (’019 m.) larger than that of the disks of gun-cotton inserted in them; had 
the diameter of the latter corresponded more nearly to that of the tube, detonation 
would have been effected by transmission through a greater length, as was demon- 
strated by several experiments; thus 2 ounces of gun-cotton, T75 inch ( 044 m.) in 
diameter, detonated in one extremity of a tube 3 feet (-91 m.) long and 2 inches 
(•05 m.) in diameter, accomplished the detonation of a disk of the same diameter 
inserted in the other extremity. 
Attempts to explode gun-cotton through the medium of tubes of considerably 
greater width were not successful. Cast-iron tubes, 3 inches (-076 m.) in diameter and 
of different lengths, from 5 feet (1-52 m.) to 2 feet (-608 m.), were employed, and 
2 ounces (62 - 4 grms.) of gun-cotton were detonated in one extremity; disks 1 inch 
(•025 m.) in diameter, inserted into the other extremity of these tubes, were not 
detonated. It appeared probable that the complete shattering and dispersion, on the 
instant of the explosion, of those portions of the cast-iron tube which were at the seat 
of the detonation might operate against the effective transmission of the concussion 
through the tube (and such was demonstrated to be the case in corresponding experi- 
ments with dynamite) : the experiments were therefore repeated with the employment 
of wrought - iron tubes 2 - 75 inches (0-069 m.) in diameter, ranging in length from 
6 feet 6 inches (2 m.) to 2 feet 10 inches ( - 858 m.) ; but only negative results 
were obtained ; the detonation of the charge in one extremity of the tubes shattered 
the gun-cotton disk in the opposite extremity, inflaming portions, but the latter was in 
no instance detonated. 
A few experiments were made with tubes of different materials, with the view of 
examining into the influence exerted by such variation upon the transmission of 
detonation. A tube 1-25 inch (-031 m.) in diameter and 2 feet (-608 m.) long was 
constructed of several superposed layers of strong brown paper. The detonation of 
1 ounce of gun-cotton inserted in one extremity did not accomplish the explosion 
of gun-cotton in the other end ; the disk was dispersed in fragments, some of which 
were inflamed, and the tube was torn to pieces. Detonation would have been induced 
with certainty by that quantity of gun-cotton in a thin wrought-iron tube of the above 
dimensions, and in a stout tube of that material with half the quantity, as already 
shown. With employment of a lead tube of the given dimensions, but slightly stouter 
in substance than the thickest wrought-iron tube used, detonation was induced by 
means of 1 ounce of gun-cotton : the metal composing the tube was opened up and 
