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512 NATURE [March 30, 1882 
premature panic, or being too remote from the point | M. Maxim’s proposal is to institute such a preventive 
attacked by the fire, reach it only too late to arrest its | system that, as soon as a fire begins to show itself at any 
progress. / given point of the stage, the accident will itself produce 
Under those circumstances M. Maxim thought it ad- | automatically and instantaneously a series of mechanical 
visable to make use of se/f-a: ting measures ; and for that movements sufficient to flood the threatened part with 
purpose has formed a combination of very ingenious ap- | water, and arrest the progress of the fire. These move- 
pliances, the principle of which be now proposes to explain. , ments are produced either by the mechanical action of 
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Fic. 1.—Apparatus closing the circuit and opening the tap. 
levers, or by electricity ; and we proceed to examine the | are set free, and thus open the ‘corresponding escape- 
two systems separately. cock, and allow the compressed air to escape from the 
Mechanical System.--The part over the stage, and the | system of pipes. This depression of the compressed air 
spaces beneath it, the side-wings, and the ceiling-decora- lowers a valve, which sets free a weight acting on the 
tions, are traversed by a network of pipes of different | supply-cock. The latter being thus opened, the water 
diameters suitably distributed. These pipes are all from the main passes throughout the system of pipes, and 
connected with a common pipe in communication with | is at once discharged by the openings corresponding to 
the main water-supply of the town. In the usual condi- | the strings which have been burned. Thanks to this 
Fic, 3.—Opening of a)ipe by the passage of « current of electricity. 
Fic. 2.—Opcening of a pipe by burning a string. 
tion, the system of pipes about the stage is full of air arrangement, a simple movement, caused by the rupture 
slightly compressed, and the supply-cock is closed. At of a combustible string, is sufficient to act upon all the 
regular intervals cocks are placed on the pipes and kept | discharge-cocks, flood the part which is in danger, and 
also closed by means of small levers, each of which is | prevent the fire from spreading. 
held in position by a string drawn tight, and fastened to a To cause a discharge of water at any given point, M. 
point at a suitable distance from the corresponding escape- Maxim also makes use of short combustible strings s¢ 
cock. As svon as the fire shows itself at any given point, | hanging, that when set on fire they cause an explgs!on 2 
by the burning of one or more of the strings, the levers | a little gun-cotton placed in a sort; of a cap, Ww pith shuts 
