394 
ME. E. A. ABEL’S CONTBIBTTTIONS TO 
gun-cotton containing about 20 per cent, of water was packed in the strong wooden 
boxes already described, which were placed upon tables in a light wooden shed. They 
were then surrounded by wooden shavings and chips, which were fired with the aid of 
some coal-tar naphtha. Eighteen minutes after the fire had been kindled, the shed 
itself was in flames, and not long afterwards the boxes could be seen burning upon the 
ground, the supports having been destroyed by the fire. The heap continued to burn 
for about three quarters of an hour, by which time the whole of the gun-cotton and 
woodwork had disappeared. At no stage during the experiments was any flame visible 
which could be positively identified as that of burning gun-cotton. 
The apparent immunity of compressed gun-cotton, if sufficiently moist, from any 
tendency to explode when submitted in considerable quantities to the prolonged effects 
of a high temperature, needed confirmation by experiments upon a still larger scale, and 
of a more severe nature, before it could be considered satisfactorily demonstrated that 
the conditions essential for developing the detonation of moist gun-cotton, namely the 
sufficient desiccation and subsequent detonation of some portion of the highly heated 
substance, might not possibly be brought about during the prolonged exposure of a 
great quantity to powerful heat. Two large experiments have therefore recently been 
instituted by the Government Committee on Gun-cotton, of which the following is a 
brief account: — Two small arched buildings, or magazines, were very strongly con- 
structed of concrete and brickwork, the walls being 2 feet thick and the arched roofs 
9 inches thick. Each magazine was provided with a wooden door, and with a staging 
1 foot 8 inches high, which consisted of four brickwork pillars with pieces of railway- 
bar joining the two on each side together and supporting broad cross bars of wrought 
iron. In one magazine a tank of the dimensions now used for storing wet gun-cotton 
in, and constructed of stout pine coated internally with a pitch-composition, was placed 
upon the staging, and 4480 disks (or 2240 lb.) of gun-cotton were packed into it, the 
lid of the tank being then securely screwed down. A similar quantity of gun-cotton, 
packed in eighty stout and tightly closed boxes, each holding 28 lb., was placed in the 
other building, the boxes being piled on the staging as close together as possible. The 
gun-cotton, in both experiments, Contained about 30 parts of water to 100 of the dry 
material. A large quantity of wood shavings and other inflammable materials was 
placed under the staging and round the gun-cotton packages in each magazine and set 
fire to, the doors being left ajar. The entire contents of both buildings had burned 
away, without any explosion, in rather less than two hours. The heat to which the 
gun-cotton, or portions of it, had been exposed was very great, as was demonstrated by 
the condition of the buildings, and the distortion of some of the wrought-iron bars, 
when the conflagration had subsided. The brilliant yellow flame characteristic of the 
burning of a mass of gun-cotton was not observed at any period throughout the expe- 
riment ; but about one hour after the fires were kindled, considerable volumes of a pale 
yellow lambent flame, occasionally exhibiting a greenish tinge, issued from the doors. 
In the case of the magazine which contained the gun-cotton in separate boxes, there 
