for extinguishing accidental Fires in Ships. 103 



In the preceding remarks we have pointed out the prin- 

 ciples that oiu^ht to be kept constantly in view in every at- 

 tempt to extu":^guish fire on board a ship. That we might 

 not interrupt the connection we purposely avoided men- 

 tioning another mean which it might be advisable to pro- 

 vide a^rainst such accidents, and which depends on the same 

 principles. The methods already laid down, it ioUowed up 

 with firmness, cannot fail to answer the purpose intended ; 

 but what we are going to mention would prove a most 

 powerful auxiharv. 



We have already noticed that the presence ot oxygen in 

 <:ombination with caloric is an indispensable requisite in the 

 process of combustion, and that atmospheric air contams 

 these two inoredients in such a state of combination, and 

 therefore ser\"es to maintain combustion by giving up its 

 oxyccn to the combustible body, in consequence ot which 

 its' caloric is liberated. It follows from this, that the sub- 

 stitution of any gas for atmospheric air, or the Introduction 

 of am/ iras into the interior of the ship, to displace the whole 

 or a pcirt of t lie atmospheric air contained in it, icould hasten 

 the extinction of the fames, provided the gas so substituted 

 for air be one that cannot be decomposed by the action ot 



the fire. , ., j i i 



It ouo-ht to be a gas that can be easily procured, and also 

 one spcxificallv he^ivier than atmospheric air, that it may 

 descend, get below the common air, take its place in tlte 

 vessel, and thus be certain (when a sufficient quantity i? 

 introduced) to reach the place on fire, and interpose itselt as 

 a wall of separation between the burning materials and the 



atmosphere. . ,, , , j r .1 • 



Carbonic acid sjas, or fixed air, is well calculated tor this 

 purpose. It can be procured even onboard a ship with 

 little trouble (if the proper requisites have been provided), 

 and at a small expense. It is considerably heavier than 

 common air, and extinguishes fume in a moment. 



All that is necessary to insure a supply ot any quantity 

 in a verv few minutes is, that each ship should be turnished 

 with a certain stock of common oil of vitriol, (vinegar or 

 any other acid would answer, but would be more expensive,) 

 and a quantity of common chalk or unburnt hme. 



The sulphuric acid or oil of vitriol is an article ot a much 

 less dangerous nature, with respect to accidents, than is 

 vulcrarly believed. Compared with gunpowder, which means 

 arelbund to keep safe, even in a ship, it may be considered 

 as perfectly harmless. Indeed, it ought to be put on board 

 in a diluted state; and, in that case, would produce no 

 Q 4 more 



