FORTY YEARS’ ACQUAINTANCE WITH FIRE MATTERS.
It may be proper to offer some explanation on chemical engines, inasmuch as several years ago I was sharply criticised because I had not given the preference to carbonic acid gas over spray in extinguishing fire. I asked for an explanation of the philosophy of the action of chemical extinguishers, but no answer has ever been given that I know of. Deeming a knowledge of the subject essential to a clear understanding of the art of extinguishing fire, I will say that fires may be extinguished by cold or excluding the air or diluting the air with some neutral substance. As a proof, take a glass fruit jar, put a spoonful of bicarbonate of soda, add to it a wineglassful of suphuric acid ; the acid will unite with the soda and liberate the carbonic acid ; now put into the carbonic acid wh ch oc .upies the upper part of the jar a red-hot piece of iron (a piece of railroad iron will answer); it will remain red-hot some time ; then withdraw it and put it into cold water and it will cool immediately. This shows very clearly that carbonic acid does not Extinguish fire by cooling it. Now put a piece of blazing paper into the carbonic acid and the flames will be extinguished instantly. Tnis does not account or explain the extinguishing power of chemical engines by any means, so I will go further. The carbonic acid in chemical engines is liberated in a close vessel under pressure; the water absorbs several times its volume of gas, and as soon as the stop-cock is opened the water and gas are driven out by the pressure of the gas in the upper part of the tank ; and as soon as the water and gas are outside the tank, the gas begins to expand, and as the velocity of the stream is diminished the expansion of the g.ts becomes greater, and if it has sufficient distance to go it is converted into a fine spray. So the very substance which my critic has requested me to subject to his superior carbonic acid, is the prime factor in extinguishing fire espec ally. Is that so when any considerable amount of .ed-bot charcoal has been found? To get a clearer idea of this subject, let us suppose the nozzle to be three-eighths of an inch in diameter and the surface of fire which the spray strikes to be four inches in diameter ; the covering surface will be one hundred and thirteen times greater than the stream when it left the nozzle. Is there any wonder that the chemical engines have such a high reputation as they have? I do not caie whether a spray is produced by the intervention of chemical agency or by direct mechanical agency. 1 have nothing to do with the invention of chemical engines ; nevertheless, I say they are an excellent auxiliary when properly used at the right time, which is at the early stages of a fire. The tapidity with which they can be brought into action is of very great importance and requiring comparatively little skill in using, but their sphere is limited on account of the life-destroying gas which is the element of their vitality, while a spray derived from water only is perfectly harmless and the best protection from cither diffused or radiant heat that is known. Besides there is no need of stopping to charge up with chemicals and water. The late fire in Illinois, where so many lives were lost, might have been arrested if the building could have been filled with the poisonous gas, hut I don’t intend to advocate any measure that will save a building at the expense of human life. Same time ago there was a statement in the fire papers that one pound of carbonic acid gas was equal to forty pounds of water in fire extinguishment. I think this is probably true, the way water is applied. I hope to have the pleasure of showing those engaged in fighting fire that there is some progress being made in fire matters, and that it depends very much how water is applied as regards its extinguishing powers.
In summing up, I must say that it is only at short and moderate range that the highest percentage of water can be utilized, and then it must be delivered in the condition of fine spray and high pressure. There are two reasons why high pressure is indispensable. It is well known that any missile projected into the air soon falls to the ground ; one cause is the attraction of gravity and the other the resistance of the air, and as a spray of sixteen thousand particles to the cubic inch presents twenty times more surface to the air than a solid stream does, the need of high delivery pressure is apparent. The other reason for using high pressure is not so apparent—it is nquited to overcome the coheson bet ween the panicles of water. If you place a tumbler on a level table and fill it carefully with water, you may see tnat t ie water will stand above ihe line of the tumbler. This is due to the particles of water. If you now place a fine needle carefully on the surface of the water it will float, and if you look close you will see the needle make a furrow where it rests. But the most familiar illustration of the coheson of water are the “drops of water that does adorn the rugged thorn when wet with pearly dew.” It would be an interesting problem to determine how many foot-pounds of power it would require to convert a gallon of water of forty degrees into a spray of two million particles to the cubic inch. As water in the condition of spray cannot be used at all times to the best advantage, it is no reason why it should not be used wherever possible ; and as there are good devices in existence by which the water can be graduated according to the distance from the fire, I can see no reason why there should be such an adhesion to solid streams only. The adoption of Siamese couplings does not seem to have been attended with any great success if we may judge from the amount of fire losses during the past year. High pressure of the pipe means higher pressure at the engine, and when the engine is a consider-able distance from the fiie it is difficult to get the required delivery pressure high enough, as the loss of pressure per hundred feet of hose is about seven per cent. If two engines are in use it will be better to put one near the fire and the other at the water, for it is better to deliver one good spray than either two poor sprays or poor solid streams. As water is what is used for extinguishing fire it is supposed that the more thrown on the fire the better. This is a mistake. If half the water that is generally used was applied with the extra force that would be required to throw the other half, the result would be much better. While I strongly recommend spray where it can reach the fire, it would be foolish to use it where it cannot. Where it is necessary to throw a great distance, a solid stream must be used ; but remember that in so doing we sacrifice quantity of effect to certainly. Where it is necessary to throw a stream at right angles to a brisk wind, a large solid stream may be used with advantage, and in this case only. It requires a very limited knowledge of figures and common sense to perceive that large solid streams cover the least surface, absorb the least heat, generate the least steam, extinguish the least fire and do the most damage with water. Let us now compare a two-inch solid stream with four-inch nozzles and delivering a spray covering twenty square feet of surface, or eighty feet in all. Can any man possessed of common sense fail to see that the spray must have the advantage ? If there is I would like to test the matter with him if opportunity presents. It looks to me that the advocating and resorting to large solid streams is an eflort to accomplish by force what ought to be accomplished by science and skill. I think the burning of the Masonic building in New York is an illustration of the case if the report as to the amount of water thrown (not used) is correct.
It is possible there may be some readers of THE JOURNAL who may wish to know what my idea of the utilization of water is in extinguishing fire. I will tell these that it consists in making water absorb all the heat it can. For instance, if we take a pound of water at forty degrees and so dispose it that it will absorb 172 units of heat, it will bring it up to boiling point ; but if we can expose it in such a manner that it will be converted into steam, 960 units of heat more will be absorbed. It is not claimed that any considerable percentage of water can ever be fully utilized, but it is claimed that it is proper that it should be known in what direction we should direct our energies to produce the best results. Though the extremes between two-inch solid streams and two million panicles to the cubic inch is great, a careful examination of many of our advanetd industries will show that their success depends largely on what I am advocating—that is, mechanical preparation to assist chemical action. The miner grinds or stamps his ores, the tanner grinds his bark, the dyer grinds his dye wares. All these are mechanical operations for the purpose of facilitating and increasing the chemical operation they must undergo. But that which most interests civilized man is the mechanical preparation of his food. Supposing at the late convention in New Orleans, when the delegates were invited to a banquet, on entering the dining hall they had found everything requisite for a firstclass repast with the single exception of bread, and in place of bread a bowl of clean, dry, white wheat placed at the side of every man’s plate with a printed card on it, “ Please to swallow the wheat without chewing.” Would it not have been thought very barbarous treatment ? But how much more so is it than a great many firemen treat fires? No doubt the pre-historic mar, dispensed with the services of both miller and baker, but is that any reason the civilized man should ? Water in some cases will subdue fire no matter how thrown on, but is it any reason why we should persist in applying it in the most primitive manner when appliances are to be had which will perform the work from five to ten times quicker?
I have given a few instructions relating to fire service, but the best method that I can think of is to prove by actual trial whether spray or solid stream is the best. In 1865 a test was made in Hartford at which the spray proved immensely superior. The laws of nature are the same now as then, but the art of extinguishing fire has advanced one hundred per cent. It has long seemed to me that the best place to give instructions to firemen would be at firemen’s conventions. With this idea, and the great inducement* held out by Rochester firemen in 1882, I sent a representative fully prepared, not to tell how to extinguish, but to extinguish actual fire, not with solid streams, but with spray varying from a few thousand up to half a million particles to the cubic inch, but as no facilities were offered no information could be imparted. This State convention will be held in Utica next August; what inducements will be offered to inventors I know not, but this I do know, that the citizens of Utica have it in their power to make the forthcoming convention the most valuable and instructive to firemen that has ever been held in this or any other country.
LITTLE FALLS, N. Y. CHARLES OYSTON.