370 
ME. E. A. ABEL’S CQNTEIBTJTIONS TO 
Four 9-ounce (280-8 grms.) disks of gun-cotton, containing about 30 per cent, of 
water, were placed on either side of a similar disk of air-dry gun-cotton, with spaces of 
1 inch (-025 m.) intervening between it and them. The detonation established by the 
dry disk was only transmitted to the nearest on each side, the others were broken up 
and scattered by the explosion. With a row of pieces of air-dry compressed gun-cotton, 
28 feet long, the disks used being 3 inches (0-75 m.) in diameter and ranging in weight 
from 2 to 2'5 ounces (56 to 70 grms.), and the contact being continuous throughout, deto- 
nation, when established at one extremity, continued to a distance® of 42 feet (12-76 m.), 
the entire length of the train. In another experiment, similar in all respects, except 
that the disks employed ranged in weight from 2-5 to 2-7 ounces and were saturated with 
water, detonation extended likewise to the entire length of the train ; the destructive 
effect, and the velocity with which the detonation travelled, being the same at the end 
as at the commencement. When disks of the same diameter, but of even higher density 
and of greater weight (consisting of 4-5 ounces of air-dry gun-cotton), were employed, 
saturated with water (containing about 30 per cent.) and arranged with intervening spaces 
of 0-5 inch (-013 m.), the detonation being established by the explosion of a 9-ounce 
(280-8 grms.) disk in contact with the first of the train, only two of the wet disks were 
detonated. In a second precisely similar experiment, except that the initiative deto- 
nation was produced by the explosion of 18 ounces (561-6 grms.) of dry gun-cotton, 
only the first five spaced disks were detonated ; and in a third experiment, with disks 
of the same weight and containing the same amount of moisture, but separated only 
by intervals of 0'25 inch (-0062 m.), ten disks were detonated, 9 ounces of dry gun- 
cotton being used as the initiative detonator. It appears, therefore, that contact of the 
distinct masses is essential to the transmission of detonation through any considerable 
number, by wet gun-cotton, in open air. It has also been established by experiment 
that the same condition is essential, even when the wet gun-cotton is confined, unless 
the strength of confinement is sufficient to resist the destructive action of the initiative 
detonation. 
It has been amply demonstrated by careful experiments that the gun-cotton prepa- 
rations which have been described just now as “nitrated” and “chlorated” may be 
as readily detonated in the moist state as ordinary compressed gun-cotton, and under 
the same conditions. These preparations absorb less water, as might have been anti- 
cipated, than the comparatively porous masses of gun-cotton itself, even in its most 
highly compressed condition. The cakes of nitrated gun-cotton, when removed from 
the press, contain not more than about 8 per cent, of water, and the maximum amount 
which they will absorb does not exceed 28 per cent. 
Numerous comparative experiments on a small and large scale have been instituted 
with moist and wet gun-cotton, both in the ordinary and “ nitrated ” forms, with the 
object of ascertaining whether the mechanical effects of its detonation differ from those 
obtained with these materials in the air-dry condition ; and no evidence whatever has 
been obtained of a falling off in the work done by gun-cotton (or by the “nitrated” 
