SPRAY BETTER THAN CARBONIC ACID GAS.

SPRAY BETTER THAN CARBONIC ACID GAS.

[CONTRIBUTED PAPER.]

In THE JOURNAL of March 30, 1878, appeared a criticism on an essay on extinguishing fires, which was printed two weeks previous, in which I recommended applying water in the condition of spray instead of a solid stream in all cases where spray could reach the fire. The writer very sensibly conceals his name, and borrows that of "Bicarb." As his letter is a very interesting compound of truth, prejudice and error, I shall dissect a few of his arguments, which I have no doubt will prove both amusing and instructive to the readers of the JOURNAL. He says: "lo throw spray on a hot fire is to convert it at once into steam, which will at once escape into'the air.” Thank you, " Bicarb," for this great and important truth. That is just what it 'will do, and it is exactly what we want. To let me illustrate: Suppose you had the charge of unloading a boatload of corn, and that it had to be carried off in sacks on the backs of laborers. As soon as one had got as much as he could carry, you would want to make room for another. Just so with water ; as soon as one portion has taken up all the heat it can carry, the sooner it gets out of the way and makes room for another the better. If all the water that is thrown the first five minutes on a fire could be converted into steam we should have very few large fires. “ Bicarb " says : “It is a well known fact that concussion or the force with which a stream is thrown against a burning object has nearly as much to do with extinguishing the fire as the quantity of water used.” Now. instead of this being a well-known fact, it is a popular fallacy—a natural result of unfamiliarity with the subject in qcstion. Weight and velocity are what produces the concussion. How will “ Bicarb” explain the action of carbonic acid gas, which he claims is so much superior to water, when the gas has less than one five-hundredth the weight of water. Some explanation is needed here. He further says : “A stream is not directrd against the flame, but against the material from which it originates.” This is a general practice, I admit; hut does that prove that it is right? I think not. As flame is the principal propagator of fire, our first business ought to be to kill the flame and then extinguish the solid carbon. It frequently happens that the flame matter originates where we cannot reach. This was the case, I understand, in the burning of Shaw’s crockery siore in New York some years ago. The fire originated in the cellar, and as it could not be got at, and as no means were at hand for extinguishing the flames, the building was destroyed. Had the Department been provided with a few spray nozzles, delivering two hundred thousand particles to the cubic inch, I have no doubt but that tin y would have conquered the fire at once.