READERS’ QUESTION BOX

READERS’ QUESTION BOX

Firemen in Theatres

TO THE EDITOR—Does the slate law require the presence of firemen in theatres during a performance?

Respectfully yours,

CHEMICAL ENGINE CO., NO. 1.

Olean. N. Y., January 24, 1914.

There is no state law relative to firemen being stationed in theatres during a performance.

The Chimney Spark Problem

To THE Editor:—What is the best method for preventing fires caused by sparks from chimneys or flues? I have had several fires at one residence each of which was caused in this way. Thanking you in advance, I am,

Respectfully yours,

E. N. K.

Columbia, Mo., January 24, 1914.

A means quite often employed is the placing of a cap over the chimney, allowing the corners to rest on legs.—Editor.

Technicalities of Fire Fighting

To THE Editor:—Will you kindly answer the following questions:

In a building 148 ft. or twelve stories high, located on the opposite side from a fire, the street being 80 ft. wide, the building is equipped with size standpipe required by law, and engine is located at a hydrant 450 ft. distant from the standpipe, and another engine at hydrant 300 ft. from the standpipe with 3-in. hose. You are in command of one of the engine companies and in company operation with the officer in command of the other company are directed to proceed to the roof, Siamese the two companies in the best possible manner in order to deliver an effective single stream across the intervening space. Explain in detail what fittings, tools, hose and nozzle you would use to properly carry out this order, and assuming that you required a nozzle pressure of 100 lbs., what pressure would you order on the pumps of the engines?

C. A. T.

New York, January 20, 1914.

The above question calls for these two answers. Pressure to be ordered on pumps, practically all they can give, technically or theoretically, 260 to 275 lbs. Tools required, perfection pipe holder, 1 1/2-in. open nozzle, roof rope, ax, Siamese 2-2 1/2-in. into 1-3 ½-in. with 3 ½-in. to 3-in. reducer, one length 3-in. hose and two lengths 2 1/2-in. hose. Reason for carrying and manner of using above tools—ax to break locks or doors to get to roof—connect one length 2 1/2-in. hose to top floor standpipe connection and stretch to roof. Connect second length to roof outlet and both to siatnese; put reducer on Siamese. Connect 3-in. length, put on nozzle, fasten to perfection holder and tic roof rope so line can’t get away.

Now as to pressure: 1 1/2-in. nozzle with 100 lbs. pressure delivers about 670 gallons. Rule— The square of the diameter of nozzle mutiplied by the square root of the pressure and that product by 29.7, equals gallons discharged per minute; that discharge loses by friction in the 50-ft. length of 3-in. about 12 lbs. The loss in the 50-ft. lengths of 2 ½ is 25 lbs., due to friction and increase in altitude of length from floor below; the loss in standpipe (which in New York is 4-in.) is 25 lbs., added to 65 for altitude, makes 90, and the loss for engines to standpipe is about 36; thus we have 100 plus 12, plus 25, plus 90, plus 36, equals 264. Since all engines are geared to work at not more than 300 lbs., and if they did increase to this amount no more than 5 or 6 lbs. would be added to nozzle pressure, it would be well to order all the water they could give.

READERS’ QUESTION BOX

READERS’ QUESTION BOX

“He that questioneth much shall learn much”—Bacon.

Capacity of Fire Hose

To THE EDITOR: In a recent discussion among the members of the Williamstown fire department, the question arose as to the weight of water in 50 feet of 2½-inch fire hose. Can you settle the question? If so we will appreciate it.

A SUBSCRIBER.

WILLIAMSTOWN, Mass., December 5, 1913.

Fifty feet of 21/2-inch fire hose hold 106 pounds of distilled water, or approximately 13 gallons. Fifty feet of 3-inch hose holds 153 pounds of water, or 19 gallons.—EDITOR.

What Causes Water to Flow from Artesian Well?

To THE EDITOR—Although hundreds of communities obtain their water supply from artesian wells, it is safe to assume that not one in a thousand is able to explain what causes the water to flow out of these small bores in the ground. The problem has been one of considerable study and meditation on my part, and I am afraid that it always will be. Have you any advice to offer on the subject?

Yours respectfully,

WALLACE E. HURD.

Waukegan, Ill., December 2, 1913.

[The theoretical explanation of the phenomenon is easily understood. The secondary and tertiary geological formation often presents the appearance of immense basins, the boundary or rim of the basin having been formed by an upheaval of adjacent strata. In these formations it often happens that a porous stratum consisting of sand, sandstone, chalk or other calcerous matter, is inclined between two impermeable layers of clay, so as to form a porous U tube continuous from side to side of the valley, the outcrop on the surrounding hills forming the mouth of the tube. The rain filtering down through the porous layer to the bottom of the basin forms there a subterranean pool, which, with the liquid or semi-liquid column pressing upon it, constitutes a sort of huge natural hydrostatic bellows. Sometimes the pressure of the superincumbent crust is so great as to cause an upheaval of disturbance of the valley. It is obvious, then, that when a hole is bored down through the upper impermeable layer to the surface of the lake, the water will be forced up by the natural law of water seeking its level to a height above the surface of the valley, greater or less, according to the elevation of the level in the feeding column, thus forming a natural fountain on precisely the same principle as that of most artificial fountains, where the water supply comes from a considerable height above the jet.—EDITOR.]

What Is Fire? What Is Pound Pressure?

To THE EDITOR: I am looking for some information, and hope that I am qot asking too much. The boys have been arguing for some time over three questions, namely: “What is fire?” “What is pound pressure?” “How many cubic inches are there in a pound of pressure?” The last question was asked at a civil service examination for captains in Syracuse, N. Y., about two years ago. Hoping you will give us this information, I am Sincerely yours, J. W. S.

Seattle, Wash., December 6, 1913.

[Fire is a form of chemical combustion in which flames make their appearance. There may be combustion or burning without flame, but not without heat. When a body becomes heated from any cause and wastes away, turning into something else (as, for instance, smoke and ashes), it is said to undergo combustion. In the process of burning or combustion there must invariably be at least two things concerned. First, there must he the combustible, or the body which burns, and then there must he some supporter of combustion, in the midst of which the combustion takes place. When wood burns in the open air it is the wood that is combustible, and the air is the supporter of the combustion. As it would not burn if not exposed to air, you might ask why does the air support the combustion of the wood? The answer is that it supplies something which is essential to the act of combustion, and that something is oxygen gas. There cannot be combustion without oxygen, because in the chemical change that goes on in burning bodies the elements of those bodies unite with the oxygen to form the substance which chemists call oxides. If there is no oxygen to combine with, there will be no chemical change, and consequently no combustion. The heat and light that accompany the burning of wood or gas are produced by the combustion or oxidation of the elements composing the wood or gas. As firemen you have noticed that the flames which are consuming a building frequently die down and then burst out with greater fury. This is caused hv more oxygen having in some way been supplied to reinforce the combustion. We hope this will appear clear to you as an explanation of the question “What is fire?” Your second question, “What is pound pressure?” is a term to describe the amount of any kind of force upon a square inch of surface. Assuming that you refer to water, we would say that the pressure of water in pounds per square inch for every foot in height is 0.433 pounds. To find the pressure in pounds per square inch of a column of water, multiply the height of the column in feet by .433. Approximately, we may say that every foot elevation is equal to half a pound pressure to the square inch; this allows for ordinary friction. With reference to “How many cubic inches there are in a pound of pressure?” we will take a column of water one square inch in cross section and 12 inches high. This would exert a pressure of 0.433 pounds. A pound pressure would represent a head of (1 / 0.433) 2.31 feet, or a column one square inch in cross section and 27.72 inches in height. This is equivalent to 27.72 cubic inches of water.—EDITOR.]