THE HISTOEY OF EXPLOSIVE AGENTS. 
383 
which had obviously been affected by some slight retardation in the breaking of the 
wire. The following were the recorded rates of travel : — 
Eate of transmission of detonation 
per second. 
0' 
and 4' 
= 19,751 feet 
(5925-3 
m.) 
4' 
„ 8' 
=19,751 „ 
(5925-3 
») 
8' 
„ 12' 
=19,006 „ 
(5701-8 
„ ) 
12' 
„ 16' 
=20,281 „ 
(6084-3 
») 
16' 
„ 20' 
= 18,928 „ 
(5678-4 
» ) 
20' 
„ 24' 
=17,608 „ 
(5282-4 
24' 
„ 28': 
=19,169 „ 
(5750-7 
») 
In another experiment the mean velocity was 19,664 feet (5899-20 m.) per second. 
The following records were obtained at 6-feet intervals, with a train of the wet disks 
36 feet long : — 
Between O' and 
„ 6 ' 
„ 12 ' 
„ 18' 
„ 24' 
„ 30' 
Eate of travel of the detonation 
per second. 
6'=22,574 feet (6772-7 m.) 
12'=18,404 „ (5521-2 
18'=19,916 „ (5974-8 
24=20,036 „ (6010-8 
30'=19,516 „ (5854-8 
36'=19,24Q „ (5772-0 
Mean velocity =19, 948 „ (5984 - 4 
ahont 15, others 30 per cent, of water ; they were arranged in a continuous train, of which the first 25 feet 
consisted entirely of the least wet disks, the remainder being composed of those saturated with water. When 
detonation was established (by means of an 8-ounce disk of dry gun-cotton), it was transmitted from disk to 
disk, in the first 25 feet, at a rate of 18,000 feet per second, but was arrested by the first disk containing the 
higher proportion of water, which, besides the two next following, was shattered and dispersed by the explo- 
sion. It has been shown that the detonation of gun-cotton containing 30 per cent, of water could not be 
accomplished by the employment of less than about 4 ounces of gun-cotton as the initiative detonator ; in the 
above experiment, therefore, in which the train consisted of disks weighing only about 2-75 ounces (85-8 
grms.), the detonation being transmitted by each disk to the one next in succession, it was consistent with 
former experiment that the last of those disks in the train which contained 15 per cent, of water should fail 
to transmit detonation to the first of the disks containing 30 per cent., although they were in contact. But in 
other experiments with trains which consisted entirely of disks containing 30 per cent, of water, and weighing 
only between 2-5 (78-0 grms.) and 2-7 ounces (84-24 grms.), detonation, established by means of an 8-ounee dry 
disk, was transmitted, without fail, throughout the longest trains experimented with (45 feet), provided the 
disks were in contact. Detonation was therefore transmitted to gun-cotton saturated with water by disks 
which contained the same proportion of water , but which were far too small to have produced this result had 
they been dry, or had they contained only 15 per cent, of water. These apparently anomalous results appear 
to indicate that the quality of detonation developed by gun-cotton is modified by the proportion of water which 
the latter contains. 
