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XV. On the Means most proper to he reported to for ex- 

 tingidskmg accidental Fires in Ships. By Alexander 

 TiLLOCH. Read before the Askesian Societrj in December 

 ISOK 



Xt is impossible for human imagination to conceive any 

 calamity more horrid and distressing than that of a ship on 

 Jire,' — a species of accident to which vessels are much ex- 

 posed, owing to the combustible nature of the materials of 

 which they are constructed, and which, unhappily, too 

 often baffles every effort to subdue it. 



To discover some means by which those on board, in 

 such circumstances, may extinguish the flanaes efficaciously 

 and speedily, has long been a desideratum ; for experience 

 has but too fully proved, that buckets and fire-engines, with 

 water, the methods heretofore resorted to, are not effectual. 

 To point out such n)eans as arc calculated to arrest the pro- 

 gress of the devouring flames will not be thought an useless 

 labour; nor will they be the less valued for being ^iwp/e, 

 and, in almost every case likely to occur, perfectly witliin 

 the reach of the people. That the efficacy of the means to 

 be proposed mav be established on incontrovertible prin<» 

 ciples, it may be oF some use to examine, previously, what 

 takes place in deflagrations of the kind to which we allude. 

 This inquiry will also probably lead us to a knowledo-e of 

 the cause why the methods usually employed prove inade- 

 quate to the end proposed. 



The laws and operations of nature are extremely simple, 

 and, if we attend to what she points out, we cannot be 

 misled. 



For maintaining the common process of combustion, 

 certain condifion> arc indispensable. 



1 . A substance or substances capable of undergoino' a 

 chemical decomposition, and of cntcrinsr, wholly or par- 

 tially, into new combinations when circumstances favour 

 the process. 



Such are wood, tar, hemp, &c. 



2. The presence of some other substance which, by its 

 decomposition, may furnish a principle or principles capa- 

 ble of entering into union with those of the combustible 

 substances, thereby liberating caloric or the matter of heat, 

 which, with the light also liberated, constitutes the most 

 striking phaenomena in combustion. 



Atmospheric air is such a substance. 

 It is a fact well known, that the atmosphere consists of 

 Vol. 21. No. b2. Marck 18u3. G two 



