PREVENTION AND EXTINGUISHMENT OF FIRES. 159 



we shall increase the efficiency ot the water and at the same time reduce 

 the quantity required, thus taking at least one step in the direction indica- 

 ted in the foregoing paragraph. 



The principal gases which are soluble in water and also incapable of sup- 

 porting combustion, are carbonic acid gas and sulphurous acid gas, both of 

 which are readily and cheaply produced and easy of application for the de- 

 sired purpose. Carbonic acid gas is soluble in water to the extent of about 

 volume for volume, and is so well known as an extinguisher of fire that it 

 has been used somewhat during many years for the suppression of confla- 

 grations, both in the well known " Phillip's Fire Annihilator," a machine 

 in which it was produced, combined with steam generated at the same time 

 and forced upon the flames through pipes, and more recently in the Babcock 

 and other "extinguishers," in which it is generated over cold water which 

 jt impregnates and forces rapidly out by its expansion. It is proposed to 

 construct similar machines for the generation of carbonic acid in the base- 

 ments of factories and business houses, with pipes leading to various por- 

 tions of the building, by means of which this gaseous water ean be speedily 

 prepared and applied directly where it is demanded. 



The English Mechanic, March, 1871, published a description and illustra- 

 tion of a fire engine on an entirely new principle, which consisted in charg- 

 ing the water used with carbonic acid gas and nitrogen, obtaining the car- 

 bonic acid by drawing atmospheric air through a charcoal fire and forcing 

 it into a tank containing water. It is claimed that one cubic foot of this 

 solution is capable of doing as much execution in extinguishing flames as 

 fifty cubic feet of ordinary water, and in one-twentieth of the time. Whether 

 this invention has been brought into practical use I do not know. These 

 machines, or at least this application and use of carbonated water or vapor 

 by some machine have the elements of success within them, since one gallon 

 of water saturated with carbonic aeid gas is equal in extinguishing power 

 to ten of ordinary water, not to recapitulate the other advantages possessed. 



Sulphurous acid gas is soluble to the extent of more than thirty times its 

 volume of water, and is utterly incapable of supporting combustion. Be- 

 ing heavier than carbonic acid gas, as well as less energetic in its evolution 

 it will not act voluntarily in forcing the impregnated water through pipes, 

 but on account of the greater amount absorbed by the same quantity of wa- 

 ter and its equal fire quenching qualities, this defect might be profitably 

 overcome by the use of machinery operated by other forces. 



Dr. Clanney's fire extinguishing solution consists of a mixture of chloride 

 of ammonium (sal ammoniac) and water in the proportion of five ounces 

 of the salt to one gallon of water. 



III. The next suggestion is that of applying gases and vapors which 

 are non-supporters of combustion directly to burning substances by means 

 of suitable machinery. In many instances this plan is applicable where 

 neither water, nor water saturated with gases, can be used effectually, for 



