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ME. F. A. ABEL’S CONTKIBITTIONS TO 
b. Experiments with dynamite. 
The cartridges used consisted of 2-5 ounces (78 grms.) of dynamite, made up into 
plastic rolls 4 inches (T m.) long and 1 inch (0-025 m.) in diameter, and wrapped 
in waterproof paper. 
The experiments were commenced with wrought-iron tubes T25 inch (-031 m.) 
internal diameter, and 6 feet (T82 m.) long, a cartridge being just inserted into each 
end. Detonation was induced, as was the case with a nearly corresponding weight of 
gun-cotton, when the length of tube intervening between the initiative explosion and 
the other cartridge was reduced to 5 feet. 
Other experiments with dynamite, corresponding to those carried out with gun-cotton 
in tubes of 1 inch and 1-25 inch diameter, as already described, furnished analogous 
results. Attempts were made to transmit the detonation developed from a charge of 
2 - 5 ounces (78 grms.) of dynamite through cast-iron tubes 4 inches (*1 m.) in diameter, 
5 feet 5 inches (T64 m.), 3 feet 3 inches (1 m.), and 2 feet 2 inches (-666 m.) in 
length, the dynamite charges being 2 inches (-025 m.) in diameter. Only negative 
results were obtained ; but on repeating the experiments with wrought - iron tubes 
•069 m. (2-75 inches) in diameter, the detonation of the above quantity of dynamite 
produced detonation of a charge of that material in the opposite extremity of this 
tube, through a length of 5 feet 3 inches (T59 m.). This was the only indication, 
but a very decided one, furnished by the tube-experiments, that detonation produced 
by dynamite is more readily susceptible of transmission to a distant mass of the 
same material, under severe conditions, than is the case with gun-cotton. The great 
difference between the results furnished by the cast-iron and wrought-iron tubes with 
dynamite was most probably due to the circumstance that the former, which were not 
strong, presented insufficient resistance at the seat of detonation to prevent a great 
escape of force, the concussion being therefore much less completely transmitted 
through the tube. 
Eesults quite similar to those described as furnished by gun-cotton, in which deto- 
nation was transmitted to a number of distinct and widely separated charges, enclosed 
in tubes, have been obtained in experiments instituted some time since with dynamite 
by Captain Trauzl of the Austrian Engineers. 
mining operations, that modifications in the method of charging and firing blast-holes in rock &c. may he 
introduced with advantage in point of safety and expedition in working. Thus it is unnecessary to insert the 
fuse, with detonator attached, to the bottom of the blast-hole. After entering the principal part of the charge 
of gun-cotton or dynamite to the bottom, the remainder, with the fuse attached, may be just inserted a short 
distance into the hole, and the charge may then he exploded with full effect by firing the fuse ; or, in holes 
of considerable depth in hard rock, the charge of explosive agent may with decided advantage he subdivided, a 
portion only being inserted to the bottom of the hole, and the remainder at intervals of 1 foot or more, the fuse, 
with priming charge, being just inserted into the opening as above pointed out. 
