<Untitled> (After our initial meeting)
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<Untitled> (When you apply a lighted match)
When you apply a lighted match to a taper, you bring an ignited body in contact with another body which has a lower temperature, and, by contact, the second body is raised in its temperature to the ignitable point, and it unites in the combustion already commenced. The heat not being dispersed as fast as developed, the combustion is accelerated and increased without adding to it, except the necessary materials for consumption. This self-propelling power of combustion and self-accumulation of heat is a phenomenon seen in the grate, or in bodies when the point of ignition is not reached.
It therefore seams pertinent that we should make inquiry as to the causes which produce heat. Tyndall and other learned scientists hold, with much reason, that force and heat are correlative terms, and that heat can be converted into force and force into heat. Hence, when the hammer falls upon the iron, the force is converted into heat, and that the heat produced will raise the hammer to the position it started from.
The learned engineer, Stephenson, is said to have inquired of his friend Ferguson what pulled the long train of cars along as it passed them with almost lightning speed. The answer was the canny. But what gives power to the canny? The steam. And what gives power to the steam? The fire, the heat. But Stephenson said “sunbeams!” The vegetable growth that finally made coal absorbed its carbon from the sunbeams, and now carbon and oxygen uniting develop the heat, and the heat is converted into force–sunbeams, the power that is pulling the vast commerce of nations along and making all humanity neighbors–sunbeams, lifting the oceans up to the mountains, making the Niagaras, and sprinkling the vast plains so quietly, so easily, that we do not realize the mighty power.
I..ing of the hand, the step you take, the breath you take, heat is converted into force; hence the fuel must be added to replenish that consumed. There are two means or methods of developing heat, viz.: Chemical affinity or action where two or more bodies unite and form a compound ; and second, by friction or force arrested.
The ca..es that develop heat are numberless, and no doubt many of them are not observed by us. A nail driven into a board will develop heat. As it remains and rusts it develops heat. The iron absorbing the oxygen causes a slow combustion, and in time the nail is burned up. The iron being a good conductor of heat, the heat is dispersed and is impercentibie.
The next point I desire to call your attention to the differens of teratures at which different bodies will ignite.
Combustion will be carried on at much lower temperature than ignition. Any known substance will burn at some temperature. Gold will melt at 2,500 degrees, while phosphorous will ignite at say 150 degrees.
Another very important point to be noted in considering this subject is, that the condition of a body, whether in a solid mass or finely pulverized, affects the conditions, whether it will ignite or not. As a rule, the finer or more attenuated a body is, the easier it can be ignited. I cannot set a bar of iron on fire by a lighted match, but can a part of the bar. Iron burns with brilliancy in oxygen; reduced by hydrogen from finely–powdered oxide it burns readily in air–taking fire spontaneously when the temperature of reduction has not been too high. Hence we cannot definitely determine under what circumstances or at what temperature a body will burn. Another important fact plense note, i. e: that carbon eliminated from wood, coal, or oil at a low temperature will ignite at a corresponding low temperature. Carbon made from wood will iguite more readily than that made from anthracite coal. The rule is, the lower the temperature carbon is prepared–other things being equal–and the shorter duration of the process of preparation the more indammable it is, and the lower the temperature may be necessary to ignife it.
Combustion then is a chemical process, in which bodies unite to form a new compound in which heat is always present and usually light.
The usual bodies uniting are carbon and oxygen and hydrogen. Oxygen seems to have affinity for almost everything, and as it is found plentifully in air, it’s on hand wherever opportanity offers. We give the fire air (oxygen) to make it burn. Combustion may be rapid or slow. Oxygen unites very rapidly with the curbon in the blood, when the blood is spread out very thin in the lungs, while under other conditions it would unite more slowly. A compact substance burns slowly, because the oxygen cannot reach all parts of it so readily, and the heat generated by the action is dispersed or does not accelerate its action by accumulation. A barrel of linseed oil will not ignite at any common temperature, but spread the oil upon almost any pulverized vegetable product or attenuated fibre, like pulverized charcoal or cotton batts, flax, hemp, jute, &c., lamp-black, sawdust or shavings, and the rapid chemical action or absorption of oxygen may, and sometimes does, evolve sufficient heat to ignite the fibre.
Spontaneous combustion may arise from either of the following causes: 1, Chemical action ; 2, Catalytic force; 3, Fermentation; 4, Heat caused by force arrested.
Under the first class are all substances that have power of absorption of oxygen, The various oils differ greatly in their affinity to oxygen, and in the temperature at which they will ignite. A vegetable oil will generally manifest much stronger chemical action than animal oil. Cotton-seed oil will cause spontaneons combustion quicker than linseed. Oil from broom-corn quicker than either flaxseed or cotton-seed oil, another fact worthy of note. Linseed oil that has been manufactured recently has not so strong affinity as an oil of greater age. The older the oil, the more rapidly will it absorb oxygen when placed in contact with the air. Some of the substances which may unite by chemical action are linseed, cotton-seed, rape-seed, broom-corn seed, castor-beans, either by fermentation or crushing of seed, and bringing the oil to the air. All oils manufactured from them, when placed upon cotton, hemp, flax, jute, wool, hair, charcoal, sawdust, shavings, on flour, wheat, straw, rotten-wood, or iron filings, and shavings are liable to burn of themselves.
Broom-corn seed will often take fire in the open feld, in heaps, when it looks green and damp, immediately after it is threshed from the stalk. Query–Are not some of our large warehouses burned by the storage of broom-corn baled? It almiost always contains some seed which is crushed by the baling, and the oil expressed on to the dry straw, which causes spontaneous combustion.
Under the second class–developing heat by the catalytic force,–we consider the practice of mixing oils. Linseed oil is mixed with cotton-seed and other vegetable oils. Olive oil and custor oil are diluted and adulterated by various mixtures, rendering them more volatile and more dangerous.
But the mixing of lard or sperm oil with the XXX lightning manufactured from petroleum to make it more limpid, or to reduce the cost, is far more reprehensible than anything heretofore intimated. Every barrel of it not labeled and marked such per cent. lard oil, such per cent. petroleum product, will ignite at such a temperature, should be confiscated. When we consider that many of the lubricators will ignite at a temperature only a litte above summer heat, we see the peril of using them in fast-running machinery, and the only wonder we have is that every mill using them is not destroyed. Under the head of fermentation comes such instances as damp hay or straw, piles of manure, damp oat meal, damp bran or flour or malt, &c. There are other conditions than those already mentioned that affect combustion. The condition of the air, its temperature or density. The warmer the temperature the more liable to take fire; therefore, in the attic in the summer, in the boiler-room near the stove or furnace-pipe, a box of waste would ignite more redily than in a cooler place. The denser the atmosphere, the more oxygen in it, hence a torch will burn brighter in a valley than upon a mountain. Under the last head we consider those substances that need some heat that is developed by force to cause them to unite or burn or explode.
I have often thought that many fires may have originated through this source, and that nature herself, in any great laboratory, like a large conflagration, may manufacture on short order some of these terrible compounds that science is giving us glimpses of from day to day.
Then followed an instructive paragraph upon the incendiary properties of electricity, and the ease with which, under certain described conditions, it and its dangerous qualities are developed, which was received with profound attention, many novel and interesting facts and illustrations being introduced. The address concluded with the following instances of spontaneous combustion:
In adjusting a loss in connection with Mr. C. C. Dana, general adjuster of the Hartford Fire Ins. Co., for Messrs, Keith & Wood, the following circumstances occurred:–The books of the firm were taken out of the ruins the second day after the fire. They were used by Mr. Dana and myself during one day-opened and leaves turned over-the ends and outside of them blackened and charred. At night all were replaced in a new safe, with the exception of one blotter, which was placed upon a pine table designed for placing goods. The next morning the book was found nearly consumed, having burned its shape into the table. Cause-paper converted into carbon at low temperature by burning store, opening the book allowed the oxygen of the air to enter, and the absorption or chemical action ignited the Book. After the great conflagration I opened my safe eight days after the fire. I took the book of blank drafts which seemed all right, except that the edges were charred. In lees than half an hour I found them in flames.
A Mr. Carette, a druggist, reported that his children prepared a ball of old wool, oiling the same to make it more elastic, wound it tightly with cord and covered it with leather. At first the boll seemed very hard, but soon it became soft, as though filled with bran or ashes. It was cut open and found to contain nothing but a black powder. The wool and cord had been carbonized, although ignition had not taken place. Mr. Gould, president of the Munufacturers' Ins. Co., of Boston, experimented with clean woolen waste, taken from a storage warehouse on Pearl street, Boston. He piled it in an area back of his office on State street. On handling it, it was found to be very oily. It was exposed on a damp hot day in August, and in less than 24 hours burst into a flame. Mr. Gould, also, in the cellar of his own house, allowed a workman's overalls to be placed, who had been polishing a door with linseed oil. At 11:30 o'clock the same night, the inmates were aroused by the smoke. It was found to come from the cellar, and the overalls were found to be on fire. Fire was discovered in the Catholic cathedral in the bell-tower, on the 16th inst.; the cause was the spontanious combustion of the rags used in cleaning the bell machinery. Mr. S. R. Holmes, adjuster of Springfield, relates from observation where oily rags took fire last winter at Galesburg, where the rags were placed in a barrel which bad been partly filled with water, which had become frozen. Observation also indicates that there is increasing danger arising from the recent practicing of charging fabrics with different substances to give them weight. Black silks are loaded with cyanogen, an extremely inflammable and dangerous compound, and also with salts of iron. The weight is increased 50 to 100 per cent., the animial nature of the silk is destroyed, it burns like tinder if ignited, and is liable to undergo spontaneous combustion of itself. Alapacas, serges, and many other fabrics are loaded more or less, and frequently with dangerons compounds. Velorur and Ulster goods contain vegetable fiber-like jute. Cheap satinets, denims, and oily woolen or uncleansed woolen fabrics will heat and finally ignite if piled up. Oiled silk, in dry goods, millinery stocks and hat stores, is unsafe. Any cloth oiled or varnished, like oiled curtains, tarpaulins, tracing paper–the oil paper used i..r copy-book–or for duplicate copies in connection with glycerine and lamp-black, tarred felt, ..oddy, lampwick, scraps of leather or oil cloth will invite spontaneons combustion beyond a doubt. The M. D. Wells fire was caused, beyond any doubt, by the oily rags and scraps of leather piled in a heap. They used cotton-seed oil for oiling leather and wiped it with off with cotton and woolen rags.
The convention then adjourned until 3 P.M.
Editor's notes