The Wonder Book Of Knowledge Part 58

Pictorial Story of Fire Apparatus

[Ill.u.s.tration: MOTOR DRIVEN AERIAL TRUCK[47]

The 66-foot ladder of this truck is raised by the motor which drives the machine. A full equipment of scaling ladders and fire-fighting apparatus is carried.]

[Ill.u.s.tration: MOTOR FIRE ENGINE AND HOSE TRUCK[47]

One of the latest fire-fighting units. A powerful gasoline engine supplies the motive power and drives the pump which has a capacity of 700 gallons per minute. The machine also acts as a hose cart and carries a full complement of firemen.]

[Ill.u.s.tration: A CRANE NECK HAND FIRE ENGINE[48]

This engine was manned by sixty trained men and under expert operation would throw a stream of 1.53 gallons per stroke more than 200 feet.]

[Ill.u.s.tration: THE FIRST STEAM FIRE ENGINE BUILT IN 1841[48]]

[Ill.u.s.tration: THE SPLENDID HORSES BY WHICH THE HAND-DRAWN FIRE APPARATUS WERE SUPPLANTED ARE IN TURN GIVING WAY TO POWERFUL MOTOR ENGINES AND TRUCKS.[49]]

[Ill.u.s.tration: AN OLD-TIME LAFRANCE PISTON STEAM FIRE ENGINE[49]

Built in 1894, at which time it had a capacity of 900 gallons per minute. This steam engine was equipped with a LaFrance boiler. This particular engine was in service in Superior, Wis., and was in continuous service pumping water on a coal fire night and day from November 18, 1913, to February 18, 1914 (just exactly three months), during which time it was only shut down twice to replace burned-out grates and three times to replace broken springs. During all of this time this steamer was incased in snow and ice.]

[Ill.u.s.tration: GASOLINE TWO-WHEEL FRONT-DRIVE, FIRST SIZE STEAM FIRE ENGINE[50]

Seventy horse-power, four-cylinder motor; speed, 35 miles per hour; locomotive bell and hand-operated siren horn; boiler, 36 x 66 inches; suction hose, 2 lengths, 4-1/2-inch diameter; lanterns, three, fire department standard; hydrant connections; carrying capacity, four men.]

[Ill.u.s.tration: COMBINATION CHEMICAL ENGINE AND HOSE CAR[50]

Seventy horse-power, four-cylinder motor; speed, 60 miles per hour; hose capacity, 1,200 feet 2-1/2-inch hose; chemical cylinder, one 40-gallon capacity; chemical hose, 200 feet 3/4-inch chemical hose; acid receptacles, two; one 10-inch electric searchlight; locomotive bell and hand-operated siren horn; extinguishers, two 3-gallon Babc.o.c.k, fire department standard; ladders, one 20-foot extension ladder, one 12-foot roof ladder with folding hooks; lanterns, four, fire department standard; axe, one, fire department standard; pike pole, one; crowbar, one of steel held by snaps; carrying capacity, seven men.]

[Ill.u.s.tration: COMBINATION CHEMICAL AND HOSE CAR

Equipped with Junior Pump. This pump is intended to boost the pressure of the chemical tank and can also be used as an auxiliary pump. On this type of steamer the pump will deliver 250 gallons of water at 120 pounds pump pressure.

_Courtesy of American LaFrance Fire Engine Co._]

[Ill.u.s.tration: COMBINATION CHEMICAL ENGINE AND HOSE CAR

Equipped with hose reel instead of hose basket as in other types ill.u.s.trated.

_Courtesy of American LaFrance Fire Engine Co._]

[Ill.u.s.tration: THE BODY OF THIS CAR HAS A CAPACITY OF 800 FEET OF 2-1/2-INCH FIRE HOSE AND IS ALSO EQUIPPED WITH A 40-GALLON TANK, WITH CHEMICAL HOSE, FIRE EXTINGUISHER AND EXTENSION LADDER.[51]]

[Ill.u.s.tration: GASOLINE TWO-WHEEL FRONT-DRIVE AERIAL TRUCK[51]

One hundred horse-power; six-cylinder motor; speed, 25 miles per hour; locomotive bell and hand-operated siren horn; extinguishers, two 3-gallon Babc.o.c.k, fire department standard; lanterns, four, fire department standard; axes, four, fire department standard; wall picks, two; crowbars, two; shovels, two; wire cutter, one; door opener, one; tin roof cutter, one; pitchforks, two; battering ram, one; Manila rope, tackle and s.n.a.t.c.h block; pull-down hook with pole, chain and rope; rubber buckets, four; crotch poles, two; pike poles, six, a.s.sorted lengths; wire basket, one under frame; one 10-inch electric searchlight.]

[Ill.u.s.tration: GASOLINE TWO-WHEEL BEVEL-GEAR FRONT-DRIVE WATER TOWER[51]

One hundred horse-power; six-cylinder motor; speed, 25 miles per hour; one 10-inch electric searchlight; locomotive bell and hand-operated siren horn; deck turret, one, mounted; nozzle tips, three for deck turret, 1-1/2-inch, 1-3/4-inch, 2-inch; three for tower nozzle, 1-1/2-inch, 1-3/4-inch, 2-inch; hose, one 35-foot length, 4-inch cotton, rubber lined; lanterns, two, fire department standard; axes, two heavy pick back, fire department standard; crowbar, one of steel, held by snaps.]

The Story of the Taking of Food From the Air[52]

What is the greatest discovery of the last twenty-five years? Probably you will say the wireless telegraph, the flying machine, moving pictures or the phonograph, but it would be none of these, according to the _Scientific American_. This publication discussed at great length the subject of what invention of the last twenty-five years was of greatest value to mankind. First place was given not to the wonderful inventions that are so large in the public eye, but to the fixation of nitrogen from the air for fertilizer purposes. Why? Simply because this discovery stands between man and starvation. Other inventions are vastly important, but this one is vital. Looking at it from the broadest view there can be no other decision. The time is here when to feed the world is becoming a more and more difficult problem.

During the past ten years our population has increased at the rate of two per cent per annum, while our crop production has increased only one-half as fast. In six years the number of beef cattle produced in this country has fallen off about five per cent per annum. The cost of foodstuffs recently has been increasing at the rate of five per cent per annum. The hardships experienced by wage-earners, particularly in the United States, have been very great in view of the fact that the cost of food increased more rapidly than wages--at a rate approximately double.

The same tendencies apply with some modifications to the clothing of mankind. These facts point to the necessity of increasing the yields both of the food crops and the crops that are used in the making of clothing.

[Ill.u.s.tration: WRAPPER LEAF TOBACCO CROP FERTILIZED WITH CYANAMID MIXTURES. GROWN IN HATFIELD, Ma.s.s.]

The problem of decreasing the cost of living has been given far more attention abroad than it has in this country, owing to the much greater density of population in the princ.i.p.al nations of Europe. For a long time it has been known that plants require food the same as animals and human beings. Without food plants cannot live and grow, and just to the extent that plant food is present in the soil, to that extent will a crop be produced. The most important of plant foods is nitrogen. While the earth is literally bathed in nitrogen, this element is found to only a very slight degree in the soil. That is to say, the air which we breathe and in which we move is four-fifths nitrogen, yet in the richest soil there is seldom more than one-tenth or two-tenths of one per cent of nitrogen. Put on a wheat crop one pound of nitrogen and you can take off twenty pounds more wheat and forty pounds more straw than you could if you failed to make this application. One pound of nitrogen properly applied to a cornfield will add thirty-five pounds to the crop; one pound of nitrogen will produce one hundred pounds of increase in the potato crop; one pound of nitrogen will produce five pounds of cotton, without any extra labor being devoted to the production of the crop.

Nitrogen is the heart and soul of the problem of growing more crops and cheaper crops. Take any nation that produces large crop yields per acre and you will find that the nation that uses the most nitrogen per acre grows the largest crops.

For years the nations of Europe have been depending to a great extent upon supplies of nitrate of soda obtained from Chile, in South America.

Germany alone imported nearly a million tons of this salt annually before the war. Then, too, the by-products of many industries furnish a quant.i.ty of nitrogen, but all this, it was realized, furnished but a small part of what was required to combat the constantly rising cost of producing food.

For years it was the dream and life-ambition of the world's greatest scientists to discover how to make the supplies of nitrogen in the air available to plants as food. The only way that this could be done in nature was through the agency of bacteria working on the roots of certain plants, such as clovers, but this process was entirely too slow for practical purposes and could be applied on only a small acreage at one time. The free nitrogen of the air cannot be utilized directly by plants. It must first be converted into some combination with other chemicals, as a solid or liquid, which can be absorbed by the plant.

Among others who worked on the problem of fixing atmospheric nitrogen were two German chemists, Doctors Caro and Frank, who found that a compound of calcium and carbon heated to a high temperature would absorb nitrogen and retain it in a form that could be applied to the soil and serve as a food for plants.

[Ill.u.s.tration: SUGAR CANE CROP FERTILIZED WITH CYANAMID MIXTURES. GROWN IN CALUMET, LA.]

This discovery is the basis of the Cyanamid "Atmospheric Nitrogen"

industry or the making of fertilizer from the nitrogen in the air. After the discovery was made and tested on the laboratory scale it took several years to put it on a practical basis, as can well be imagined when it is understood what the problems involved were. Besides air this process required as raw materials limestone and c.o.ke. The limestone must be burned to quicklime and the quicklime and c.o.ke must be fused together to form calcium carbide. Only the most powerful electric furnaces are capable of performing this work. Any other means of heating is far from adequate. For instance, the hottest flame that can be produced by the burning of gas, namely, the oxy-hydrogen blow-pipe flame, can be directed against a stick of burnt lime without doing anything beyond making the lime glow brilliantly, thus producing the calcium or lime-light formerly much used in theaters as a spot-light. In the electric furnaces, however, the lime is heated so powerfully that it actually melts to a liquid, and in this condition it dissolves the c.o.ke with which it is mixed and the compound resulting is calcium carbide which can be run off from the interior of the furnace in liquid form.

[Ill.u.s.tration: TWO OF THE CARBIDE FURNACES AND ELECTRODE REGULATORS]

At the cyanamid plant at Niagara Falls, in Canada, there are seven of these great carbide furnaces, each about fifteen feet long and half as wide and one-third as deep. We all have some idea of how much heat is generated in the ordinary electric arc light such as is used for street lighting. In the carbide furnace the carbon pencil, instead of being six or eight inches long and as large around as your finger, is six feet long and two feet in diameter. There are three of these in each furnace, and when the furnace is in full action it can be imagined that there is a terrific heat generated; in fact, when the fused lime and c.o.ke come out of the furnace in the form of molten carbide the brightness of the molten material is so dazzling that one cannot look at it with the naked eyes without injury.

[Ill.u.s.tration: ONE OF THE CARBIDE MILLS]

Then there is the problem of producing pure nitrogen gas, that is, separating the eighty per cent of nitrogen in the air from the twenty per cent of oxygen. The latter is the element that we breathe and which pa.s.ses into the body, there to combine with the impurities resulting from the various life activities. If the nitrogen and the oxygen were both allowed to act upon calcium carbide the oxygen would burn up the carbide before the nitrogen could be fixed in it, hence these two elements must be separated and all other impurities removed so that only chemically pure nitrogen is brought to the calcium carbide for fixation.

The separation is accomplished by means of liquid air machines. This industry, therefore, not only utilizes the greatest heat obtainable on a practical scale, but it also utilizes the greatest cold. While the electric furnaces produce a temperature of over 4000 F., or about twice as hot as molten cast-iron, the liquid air machines work at a temperature of 372 F. below zero. The air must first be purified and dried. It is then compressed, cooled while under pressure, and then expanded. The expansion lowers its temperature considerably. If this extra cool air is used for cooling another batch of air under pressure, the latter upon expansion becomes still colder than the first batch expanded. By repeating this operation the final temperature of 372 below zero is reached, at which the air liquifies.

How cold this is can be seen from some simple experiments. For instance, if a dipper full of the liquid air is drawn, in an instant the outside of the dipper is covered with a coating of frost deposited upon it from the surrounding atmosphere. The surrounding air is so much hotter than the liquid air that the liquid boils violently. If a piece of rubber hose is held in the liquid air for eight or ten seconds and then struck with a hammer the rubber flies into pieces just like gla.s.s. To dip one's finger into this liquid air would freeze it solid in a second and would be as disastrous as dipping it in red-hot iron.

[Ill.u.s.tration: LIQUID AIR PLANT]

When the liquid air is allowed to warm up a little, the nitrogen gas evaporates, while the oxygen remains behind in the liquid. The pure nitrogen then can be pumped into the fixation ovens.

To fix the nitrogen in the carbide it is necessary to cool the latter after it comes from the electric furnaces and grind it to a very fine powder. This powder is then placed in furnaces that look like steel barrels but are three or four times larger than an ordinary barrel. The oven filled with calcium carbide is then electrically heated with a carbon rod running through the center. When the temperature is about as hot as that of molten iron the pure nitrogen gas from the liquid air plant is pumped in and allowed to act on the calcium carbide for about a day and a half. When the carbide has absorbed all it will absorb the crude cyanamid formed is removed from the oven as a single large cake which is run through pulverizing drums and then put through an elaborate process of refinement and finally bagged for shipment in carload lots to fertilizer factories throughout the country.