104 Protection of Persons from Fire. 
left at top for communication with the atmosphere. The animals 
thus placed, were retained in the midst of flames a much longer 
time than firemen would have occasion to remain in the course of 
their duties, in extensive conflagrations. 
Thus encouraged, the experiments were extended to mien. An 
armor was prepared for the head, whose interior surface was.a tis- 
sue of iron wire, with a double metallic gauze, which enveloped it; 
the front was closed only by the gauze. This armature descended 
to the shoulders, and rested upon them, so that the top of the head 
was not in contact with the metal, but was defended by it from ex- 
ternal blows, and being of considerable strength, and supported en- 
tirely by the shoulders, this armature is at once a fire guard, and a 
preservative against external violence. 
Thus equipped, firemen exposed their faces to the combined 
flames of twenty-four and even thirty-six candles, as well as to the 
flames of wood and straw, and held them in this position for more 
than two minutes, with but a slight increase of heat. So satisfactory 
were these trials, that several young persons who witnessed them, 
wished to make the experiment, and did so more than once. 
The difficulty of conceiving how an air of this kind can be breath- 
ed with impunity, will be lessened by the reflection that the tempera- 
ture within the mask is much lower than without; that by the agita- 
tion usual in flame the air is frequently renewed 3 that in the aif 
which is mingled with a volume of flame, the oxygen is by no means 
exhausted ; that j in such cases it is not the want of oxygen so much 
as the presence of carbonic acid, that causes respiration to become 
difficult ;.and that this foul and heated air is continually ascending 
and giving place to fresh portions of pure air. 
To guard against the effects of smoke, is another affair. The au- 
thor cites various methods which have been proposed by others, vi2- 
covering the face with a mask of sponge, except two openings closed 
by glasses for the eyes, keeping the sponge moist with water, with an 
alkaline solution, or with chlorine, as the case may require ; coveriDg 
the face with leather, to which is attached a tube three or four feet 
long, containing at its extremity a moistened sponge. ‘These are good 
precautions against smoke alone, but when smoke and flame are active 
J penmined, _ they on not sufficient, and it does not appear that the 
ropose any thing more effectual. He justly 
observes, that the existence of much smoke is an evidence that the at 
mosphere is not freely admitted to the horas materials, and therefore 
