514 
ME. E. A. ABEL’S CONTRIBUTIONS TO 
buried fuse did not displace the cylinder, but had the effect of bulging it somewhat in 
the centre and cracking it slightly in one place. A third similar cylinder was filled with 
gunpowder, and an electric fuse primed with a corresponding quantity of fulminate to 
that used in the preceding experiment, was inserted, the mouth of the cylinder being 
left quite open, as in the other instances. The explosion of the powder was attended 
by a sharp report, the cylinder was rent into several pieces, which were scattered about, 
and a cavity was formed in the ground, the earth being projected to a considerable 
distance. The effect was, in fact, similar to what would have been produced had the 
powder-charge been in a buried and tightly closed shell. Similar results were obtained 
in other experiments, confirmatory of the power possessed by a detonation to develope 
the explosive force of gunpowder, under conditions antagonistic to the violent action of 
the latter under ordinary circumstances. 
The results of a few experiments instituted with small charges of gunpowder (8 ozs. 
and 1 lb.) appeared to furnish decisive indications that their explosion through the 
agency of a detonation was considerably more rapid than when flame was applied tc 
their ignition under corresponding conditions. The charges were enclosed in sheet-tin 
cases closely resembling each other, and these were buried in the ground at depths of 
18 inches in holes of corresponding dimensions, the earth being rammed down tightly 
upon the charges in the same manner, and by the same operator, in each instance. They 
contained electric fuses which, on the one hand, were primed in the ordinary way with 
meal powder, and, on the other, with mercuric fulminate. In the instance of the ordi- 
nary fuses, the explosion of the charges produced clear holes, the earth being partly 
piled up around, and partly scattered ; but in the case of the charges fired with deto- 
nating fuses, much of the earth was thrown up vertically with considerable violence, 
but there was very little scattering effect, the hole being to a great extent filled up again 
by the earth momentarily displaced*. 
That the explosion of gun-cotton through the agency of detonation exerts a more 
violently destructive action than its explosion when strongly confined, by the simple 
agency of heat, has been abundantly proved by blasting operations in various descrip- 
tions of rock, and by measurement of the comparative destructive effect of charges 
exploded under water. Charges of gun-cotton contained in blast-holes, and having a 
detonating fuse inserted in or placed immediately over them, have produced much 
greater rending and shattering effects in hard rock and in wood (although the blast- 
holes were left entirely open, or only filled with loose sand, earth, or powdered rock) 
than corresponding charges applied in similar positions, but fired with ordinary fuses, 
although in the latter instances the gun-cotton was confined by “ tamping,” or firmly 
closing the blast-hole to a considerable depth. A series of systematic experiments have 
been carried on at Chatham by the Government Committee on Floating Obstructions, 
* The relative displacing powers of powder-charges fired under similar conditions by the two modes of igni- 
tion has since been made the subject of practical experiments at the Eoyal Engineer Establishment, Chatham 
(Nov. 1869). 
