THE ROYAL ARTILLERY INSTITUTION. 
29 
5 lbs. of powder loose in an open barrel, and 5 lbs. in five 1-lb. 
canisters (of Messrs. Curtis and Harvey, and Hall and Son). 
In every case I personally superintended the placing of the 
powder in the magazines. 
The above dispositions appeared to me fairly to represent the 
various combinations which might exist in the storage of powder 
for trade or private purposes. There was the canister powder 
hermetically closed up, the barrel powder in a closed barrel, and 
the same in an open barrel, and the powder in paper. 
For the purposes of the experiment, Messrs. Milner had caused 
to be built four furnaces of brick. The furnaces for Nos. 1, 2, and 
3 magazines were circles of brick-work, 7 ft. internal diameter, 
and about 3 ft. 6 ins. high. In order to provide a thorough 
draught, the furnaces were built with the bricks omitted at inter¬ 
vals—the open intervals serving as so many blast-holes, or 
“ twyeres,” through which the air could pass. 
The furnace for No. 4 magazine differed only in being 8 ft. 6 ins. 
internal diameter. A layer of coals and wood and shavings was 
placed inside each furnace, the magazine introduced and placed on 
bricks (so as to increase the draught), and then coals were 
shovelled in until the magazine was completely covered. 
Furnaces I to 3 took about five tons of coal each; furnace No. 
4 about seven tons. 
In order to obtain data with reference to the temperature in the 
interior of the magazines, there were introduced into each two 
thermometers (one by Negretti and Zambra, the other by Chad- 
burn) capable of registering up to about 600°. Also, and as a 
check upon the thermometers, there were introduced a number 
of sticks of alloys of tin and lead in various proportions, which 
Professor Abel had ascertained were fusible at different tempera¬ 
tures. 
There were 21 different alloys, ranging as to fusibility from 
340° to 558° Fahr. (For the details as to the composition of 
these alloys, see Appendix E.) 
The fires were lit (by means of petroleum) as follows :— 
No. 1 lit at 10.0 a.m."\ 
i, 2 « 10.30 « £ 9th October, 
u 3 „ 11.0 . t 1872. 
„ 4 „ 11.15 „ ; 
The fires soon blazed up, and in a very short time they were 
burning with intense violence. The excellent draught which 
resulted from the construction of the furnaces soon produced a 
fierce glowing mass of fire, which completely enveloped the maga¬ 
zines. I may here mention that the experiments were witnessed 
by a large number of gentlemen variously interested in the 
results, and including the Superintendents of the Fire Brigades of 
Dublin, Manchester, Glasgow, Belfast, Sheffield, Bradford, Leeds, 
&c., several of whom expressed to me personally their satisfaction 
with the completeness and searching character of the experiment. 
