Fire was probably one of man’s first, if not the first, great discoveries, and has been one of his greatest servants as well as one of his greatest dangers. We do not know who discovered fire, or what nation first used it. It is, however, one of the signs that distinguishes man from the other animals. Not any of the lower animals was acquainted with the use of fire, while probably the earliest races of mankind seem to have been acquainted with it.

Mythology tells us wonderful stories of the origin of fire: according to these tales it was stolen from the sun, or the gods, and given to man; and Pandora, the first woman, was sent down to earth to punish man for his theft.

The most popular of these stories is the legend of Prometheus. According to this legend, fire, in the early days, was under the exclusive control of the gods. Prometheus, brother of Atlas, the god who supported the world on his shoulders, determined that the use of fire should be given to the people. He decided by some means to send a spark of fire to the earth, believing that one spark caught by man would start a burning flame that would never go out.

With this idea in mind, Prometheus visited Zeus, the great ruler, to carry out his purpose, for Zeus controlled fire. While Zeus was not looking, Prometheus “stole some brands of fire from the hearth, which he hid in the stalk of a fennel and sent it down to the earth.” Through this Prometheus gave to man his first knowledge of fire.

But while this story of fire may or may not be true, the use of fire rests entirely with man and his ingenuity. Through his ingenuity man was able to subject fire to his will; making it perform certain of his labors; and to a certain extent making it his servant; although it always did and always will get beyond his control at times.

Our ancestors were not satisfied with preserving the fire which the gods gave them; they tried and succeeded in producing it. One day one of them discovered that by rubbing two sticks together rapidly, the friction would create a fire. It was a most useful discovery. Before long the whole of mankind had learned this trick; others improved on this crude method until step by step men learned that by striking two pieces of flint or other hard mineral together, quicker action was obtained.

All kinds of methods were devised to increase knowledge of producing fire. The early Greeks found out how to catch the rays of the sun on a burning-glass and produce fire; the Romans achieved the same results through the use of mirrors.

In about A.D. 900, an Arab, named Bechel, discovered phosphorus, but it took almost 800 years more for Haukwitz to learn that when phosphorus was brought into friction with sulphur, fire would result. In another hundred years the world was benefited by the invention of the friction match—and since that time about one-half the people have been carrying matches about with them, able thus to start a fire easily any time.

Fire and man’s knowledge of it have had much to do with man’s progress in civilization. Before man had fire, his life and movements were much like those of other animals. When man had learned to make a fire he was free to move and live anywhere and, therefore, people began to cover more territory.

What Would We Do Without Matches?

If one were to ask the man in the street what invention of the nineteenth century is his most constant and invaluable ally he might be mystified for the moment, but the undoubted answer would surely come in the single word “Matches.” These familiar objects, apart from their luxurious use by smokers, are the indispensable servants of mankind from the moment of rising in the morning till the household is wrapped in sleep, and it is to them we turn when disturbed in the hours of darkness.

No doubt “familiarity breeds contempt,” and it is difficult to imagine how man would fare, bereft of his box of matches. It might help the world to realize how much it owes to the inventors of the Lucifer Match, were it possible to cut off the supply of these magic fire producers for only one brief day. It requires no very vivid imagination to picture the consternation and confusion that such a step would produce, and there is a grim humor in wondering how the primitive methods of obtaining a light would serve the public convenience in these days of strenuous hustle.

Seeing that fire has been employed by man since prehistoric days, one would expect that easy means of obtaining it would have been devised in the early ages. We find, however, that until the beginning of the nineteenth century nothing in the nature of a match was available, and the crudest methods were still in use. We know from Virgil that in the reign of the Emperor Titus fire was obtained by rubbing decayed wood with a roll of sulphur between two stones, but it is not till Saxon times that we have evidence of the use of the tinder box with its flint and steel. That this latter was still regarded as something remarkable, as late as the fifteenth century, is proved by its representation in the collar of the Order of the Golden Fleece, which was founded in 1429. Burning glasses had, of course, been employed from the most primitive times, but one can imagine the despair of an early Briton who had to wait for a sunny day before he could boil his kettle.

Incredible as it may seem, it was not a time well within the memory of many people living to-day that matches in anything approaching the form now familiar were offered to the public. The way for their manufacture had been prepared by two discoveries; one by a German who isolated phosphorus in 1669; the other by a Frenchman who produced chlorate of potash in 1786. From this latter date the production of fire was much facilitated, and a few years before Queen Victoria came to the throne, John Walker—a chemist of Stockton-on-Tees—produced the first friction matches of which there is any certain record. These, called “Congreves,” were sold in boxes of fifty for 2/6, and their success soon led others to experiment in match manufacture, so that improvements were rapidly invented and factories sprang up in all parts of the country.

It would be a difficult task to compute accurately the value to the human race of the introduction to general use of this little article. At the present writing, in America the consumption of matches amounts to over a billion of matches a day.

How Matches Are Made.

To-day matches are in such demand that the ingenuity of man has devised a machine which makes complete matches without the help of the human hand.

At the very start of operations a man feeds blocks of wood into the jaws of the machine, and thenceforth the mechanical monster does its own work. Seizing the block from the man’s hand, the machine grips it between rollers and forces it against rows of keen-edged cutters, which are so arranged that there is little or no waste. Each of these cutters (and there are usually forty-eight in a machine) severs a piece of wood of exact size and shape. At the same moment a plate rises from beneath, which thrusts these little pieces of wood into a moving flexible cast-iron band, or rather into small holes in this band, from which the embryo matches project like bristles. This traveling band is about 700 feet in length, and follows a serpentine course in its journey, which occupies about an hour from start to finish, the speed being regulated according to temperature so that the matches may be quite dry when they reach the boxes.

When the band arrives at the finishing point, a steel bar punches out the matches stuck in its surface and they fall into the inside boxes placed ready to catch them. These boxes are kept continually shaking, to that no spaces are left and the matches fill them completely. As the inside boxes fill, a steel arm presses them forward into their covers, and they are passed along a trough in dozens, quickly wrapped in paper and sealed by a machine. Quick-fingered girls then wrap twelve of these dozen packages and we have the gross packages of boxes so familiar in the stores. It will be seen, that in spite of the marvellous machines which do so much, there is still plenty of work for human hands.

How Match Boxes Are Made.

The machines for making the wooden box which contain the matches are in themselves wonderful. First, a section of the trunk of an aspen tree, about 30 inches in length, is made to revolve in what is known as a peeling machine. After a few revolutions the rough outer surface is removed, and thin rolls of smooth-surfaced wood are peeled off or veneered. The machine at the same time scores the wood ready for folding by the boxmaking machine. Cut into skillets, i. e., into pieces of the size required for box covers or insides, the ends are next dipped in pink dye to cover the edge of the wood which is not covered by the label. The skillets then go to the box machines, which fold and label them, and after half an hour in a cleverly devised drying chamber they are ready for use. In one room alone sixty machines are labelling and folding the skillets to the number of several thousand gross a day. To see these machines take a strip of wood, push it forward to receive the pasted label, fold it, fasten the joint, wipe off the superfluous paste, and, finally, toss the finished “outside” into a receiving basket, is as fascinating an example of mechanical ingenuity as the industrial world can afford.

Are Matches Poisonous?

A non-poisonous “strike anywhere” safety match, made from selected, clear, strong cork pine is now made in this country, and is the first satisfactory non-poisonous match. It is also the first match to be endorsed by the country’s recognized leaders and authorities in fire prevention and the conservation of human life and property.

The Hughes-Esch Anti-White Phosphorus Match Bill, which became a law during the administration of President Taft, was drafted by the attorneys of the American Association of Labor Legislation, and is the most drastic that our National Constitution will permit. It would be unconstitutional to absolutely prohibit the manufacture of white phosphorus matches, but the Hughes-Esch bill obtains the same result, viz.: absolute prohibition by means of excessive taxation. No match manufacturer in these days of keen competition can afford to pay a tax of ten cents on each box of white phosphorus matches made, and place his factory under government surveillance, for this tax of ten cents is over three times as much as his present selling price to the wholesale trade.

As soon as man learned to make fire and light, he began to appreciate how much more comfortable he could be if he could keep his lights burning and to have his light independent of his fire, because it was at times very uncomfortable to sit by a fire on a hot night simply because he wished to use the light which it made. The first schemes devised for lighting purposes merely were the camp-fire torch and the rushlight. With these as a basis, man was enabled to fashion more convenient forms of lighting. He invented the candle and the lamp, and grown “enlightened,” boxed his light in iron and in other metals.

Did Candles Come Before Lamps?

The candle is in appearance a primitive affair, yet there is little doubt that its predecessor was the lamp. Those old Egyptian tombs, which have unlocked many mysteries, held lamps, and through them evidence of ancient burial customs. Lamps played a part in the solemn feasts of the Egyptians, who on such occasions placed them before their houses, burning them throughout the night. Herodotus, in one of his numerous references to Xerxes, alludes to the hour of lamp-lighting, and evidences abound regarding the use of lamps among the ancient Greeks. Lamps, indeed, are pictured upon some of their oldest vases, indicating the symbolic significance which attached to them.

What Were the Earliest Lamps?

It is probable that the earliest lamps were nothing more than convenient vessels, filled with oil and fired by means of rushes. Among the Romans pine splinters, the torch and the flambeau, supplied light until the fifth century before Christ, and even when the Roman began to use the lamp, it was by no means common, finding a place only in the homes of the rich, or on special festival days.

The custom of burning funeral lights beside the dead before interment is a very old one. Gregory, interpreting its significance for the Christian, says that departed souls, having walked here as the children of light, now walk with God in the light of the living. The Roman, Pliny, refers to the use of the pith of brittle rushes in making funeral lights and watch-candles, which were probably the ancient prototype of the old rushlight of England. Again, in speaking of flax, Pliny states that the part of the reed that is nearest to the outer skin is called tow, and is good for nothing but to make lamp-matches or candlewicks.

What Were the Lamps of the Wise and Foolish Maidens Made Of?

When lamps had come into general favor, better attention was given to their form and construction. The first seem to have been made of baked clay, moulded by hand into elongated vessels to contain the oil, and provided at one end with a lip to admit the wick. These are the lamps which artists have pictured in the hands of the wise and foolish virgins, though in the opinion of some scholars they were merely rods of porcelain and iron, covered with cloth and steeped in oil. Another early type, which was less common, presents a simple disc with an aperture in the centre for the oil, and a hole for the wick, at one or both of the sides.

Under the Empire, when the light of the lamp had become general, the better ones were made of bronze, ornamented with heads, animals, and other decorations, attached to the handles, while as life in Rome partook more of luxury and extravagance, gold, silver, or Corinthian brass were the materials, the designs being more elaborate and complicated. Many and beautiful examples of these ancient lamps have been unearthed from the ruins of Herculaneum and Pompeii.

When Were Street Lamps First Used?

Dark must have been the lives of those people who, until comparatively recent times, lived, in the absence of sunlight, by the feeble, uncertain light of the primitive illuminants borne by these lamps. And as for street lighting—that was a luxury but seldom indulged in, and then, not for public benefit, but to enhance the glory of a potentate, or grace the obsequies of some great man. Even Rome, at the height of her luxury and beauty, rarely exhibited more than one or two lanterns in her streets. These were suspended over the baths and places of public resort. Occasionally, however, the streets were illuminated during festivals and other public occasions, while the Forum was sometimes lighted for a midnight exhibition. With these glittering exceptions, and that memorable one when, to satisfy the homicidal impulses of a bad emperor, the bodies of Christians were made living torches, Rome was a city of darkness.

When Were Candles Introduced?

Historical records indicate the prevalent use of candles in the earliest days of Rome, but these candles were of the simplest sort—mere string or rope which had been smeared with pitch or wax. In the early Christian centuries it was the custom to dip rushes in pitch and coat them with wax, a method of candle-making that was long continued, for it was not until the fourteenth century that dipped tallow candles were introduced. In the Middle Ages wax candles provided the usual means of illumination, and these were made, not by common craftsmen, but by monks, or by the servants of the rich. Until the fifteenth century their use was confined to churches, monasteries and the houses of nobles, but the demand for them had become so great that the chandlers of London obtained an act of incorporation. As late as the eighteenth century the candles were made by dipping the wicks into melted wax or tallow, but about this time an ingenious Frenchman conceived the idea of casting them in metal moulds.

It is only within a modern period that the state or city has assumed responsibility in the matter of public lighting, which for the most part had been left to the good will and public spirit of citizens. But in England a proclamation was issued to the effect that every individual should place a candle in each of the lower windows of his house, and keep it burning from nightfall until midnight.

Paris was the first city to improve upon this method of street lighting, and in 1658 huge, vase-like contrivances, filled with resin and pitch, were set up in the principal thoroughfares. The improvement proving, as may readily be seen, both dangerous and expensive, the falct, so-called, were replaced by the lantern. This was at first simply a rude frame, covered with horn or leather, within which a candle burned. For more than one hundred years this was the extent of the illumination which the authorities could provide. But of course it was understood that no honest man would venture abroad without his torch or flambeau, and as London, Berlin, Vienna, and all leading cities of Europe, were in like case, the darkness of Paris could be borne.

But progress had been made, and early in the eighteenth century the Corporation of London entered into contract with a certain individual to set up public lights, giving him permission to exact a sum of six shillings from every householder whose actual rent exceeded ten pounds. In the middle of the same century the Lord Mayor and Common Council applied to Parliament for power to light the streets of London better. From the granting of this permission dates improvement in public lighting.

Where Did the Word “Gas” Originate?

A Belgium chemist, Van Helmont, coined the word “gas” in the first half of the seventeenth century. The Dutch word “geest,” signifying “ghost,” suggested the term to him, and his superstitious neighbors hounded him into obscurity for talking of ghosts.

When Illuminating Gas Was Discovered.

The first practical demonstration of the value of gas made from coal for lighting was made by a Scotchman—Robert Murdock—who in 1797, after some years of experimenting, fitted up an apparatus in the workshop of Boulton and Watt, in Birmingham, England, which successfully lighted a portion of that establishment. The advantages of this kind of lighting were so apparent that its use was rapidly extended, although in many instances the people were afraid of it. For a time this kind of lighting was confined to street lights. One of the first great structures to be lighted by gas was Westminster Bridge in London, and great crowds gathered to watch the burning jets nightly. It was difficult to remove from the minds of the people the belief that the gas-pipes were filled with fire and the jets were only openings through which the flame in the pipes escaped. People sometimes touched the pipes expecting to find them hot, and when the pipes were put in buildings they made sure that they were placed several feet from the walls lest the fire in them set fire to the buildings.

The use of illuminating gas for lighting private houses developed quite slowly because of this fear of the fire in the gas-pipes. This was not entirely unwarranted, however, because at first the plumbers did not know, as they do now, how to prevent leakage of gas from the pipes. The methods of joining the pipes were oftentimes imperfect and, not realizing the dangers which would follow leaks, causing explosions, the workmen were often careless in installing the pipes.

The first American house in which gas was used for lighting was the home of David Mellville at Newport, R. I. Baltimore, Maryland, was the first American city to use gas for lighting. It was introduced there in 1817.

How Does Gas Get Into the Gas Jet?

If you hold a cool drinking glass over a burning gas jet for a moment, a film of moisture will form on the inside of the glass and remain until the tumbler becomes warm, and then disappear. Now, then, you will remember that water is a mixture of oxygen and hydrogen, and that when hydrogen is burned in the air, water is formed. It is also true that whenever water is formed by burning anything, hydrogen is present in it. You see, therefore, that the gas used for lighting purposes must contain hydrogen.

Let us now learn something more about what gas is made of. Wet a piece of glass with a little fresh lime water and hold this over the lighted gas jet. In a few moments a change takes place in the water. The water turns somewhat milky. This indicates the presence of carbonic acid gas, and the formation of carbonic acid gas, when burning is going on, means the presence of carbon.

From these two experiments we gather that the gas in the jet contains hydrogen and carbon. All kinds of illuminating gas contain these two substances. Sometimes there are small quantities of other substances present, but the value of gas for lighting depends on hydrogen and carbon.

We have already learned about hydrogen, but it would be well to re-learn about carbon.

Carbon is an element, and an extremely important one, for a large part of the composition of every living thing is carbon. It is found in more compounds than any other element. Almost pure carbon can easily be obtained by heating a piece of wood, in a covered utensil, until it is turned into charcoal. Charcoal, which is black, is composed almost entirely of carbon. It is a very interesting product in all ways; in connection with gas we are particularly interested in the fact that carbon will burn when heated in the air or in oxygen.

Charcoal is very much like hard coal, both being formed in practically the same way. Ages of years ago many large forests of trees were buried under a layer of soil and rocks, during changes that occurred in the earth’s surface, and the hot inside earth slowly heated the wood, until almost nothing was left but the carbon.

Soft coal was formed in much the same manner, but the process was not so completely finished. Mixed with the carbon in soft coal we find quite a good deal of other substances, of which hydrogen forms the principal part. This is what makes soft coal valuable in the making of illuminating gas.

When soft coal is heated in a closed receptacle a gas is formed which will burn. To show this we have only to take an ordinary clay pipe, put a little piece of coal in the bowl, close the top with wet clay, and put the bowl part of the pipe in the fire. When it is quite hot, a gas will be found coming out of the stem of the pipe, which will, when lighted, burn.

The Story In a Gas Jet.

Soft coal is heated in large tubes of fire clay called retorts, and the gas that is formed is then collected in a large tank and sent through pipes to our homes after being purified. The part of the coal that is left consists largely of carbon and is what we call coke.

While the gas that comes directly from coal will burn if lighted, it is not a desirable gas to burn in our homes, because it contains a number of substances that should be eliminated before it is used for lighting.

How the Gas Is Purified.

From the clay retorts the gas passes through horizontal pipes containing water. This cools it and takes out of it most of the tar and water vapor that are driven off with the gas when formed. These substances settle in the water. The gas then goes through a series of curved pipes, which are air cooled. These pipes constitute what is known as an atmospheric condenser. From these the gas goes into a series of receptacles containing wooden slat trays, made up like screens. These receptacles are called the scrubbers, and they take out of the gas the last traces of tar and some of the other compounds found present. The removal of the sulphur is very important, for burning sulphur gives off a gas which is not only extremely impure to breathe, but also injurious to the health.

From the scrubbers the gas goes on through pipes to the purifiers—boxes which contain wood shavings coated with iron rust upon which the sulphur is deposited by chemical action. At the same time the lime absorbs a small quantity of carbonic acid gas, which is formed with the other gases. From the purifiers the gas passes into the great iron tanks, in which it is stored until needed.

The gas in the tanks consists chiefly of hydrogen, a number of compounds of hydrogen and carbon, and a small amount of a compound of carbon and oxygen containing less oxygen than carbonic acid gas, known as carbon monoxide. The hydrogen and carbon monoxide burn with a very pale flame, which gives but little light and much heat. The light-giving quality of the gas is found in the compounds of carbon and hydrogen. When these burn, the particles of carbon are heated white hot and glow very brightly, making a luminous flame.

There are, of course, some impurities in the purified gas. These are compounds containing sulphur and ammonia. The quantities of these substances, however, are so small that they are harmless; but the compounds taken out in the process of purifying the gas are saved, as considerable use is made of them. The water used for washing the gas is heavily charged with ammonia and is, in fact, the chief source of the ammonia sold by druggists.

In addition to coal gas made in the way just described, there is another form of illuminating gas, in the manufacture of which coal is indirectly employed. This gas, known as water gas, because it is formed by the decomposition of water, is produced by passing steam over red hot carbon, in the form of hard coal or coke. When this is done, the hydrogen in the steam is set free and the oxygen combines chemically with the carbon, to form the carbon monoxide, that was mentioned as being present, in small proportions, in ordinary coal gas. This carbon monoxide is poisonous, if much of it is breathed, and as it has no odor it is difficult to detect when escaping. A number of deaths have resulted from water gas for this reason, and in some states the laws forbid its use for lighting purposes.

When water gas is used it must be enriched with some other substances before it will yield much light. You have already learned that neither hydrogen nor carbon monoxide burns with a bright flame, and you will see that water gas must have something added to it to fit it for lighting purposes. The substance usually added is the vapor of some light, volatile oil, like gasoline. This vapor is composed of compounds of carbon and hydrogen, and when it is mixed with the water gas it forms a gas that yields a very satisfactory light; and that may be produced more cheaply than common coal gas.

There remains one more form of illuminating gas which has been the subject of much discussion in recent years, namely, acetylene. This is a compound of carbon and hydrogen, in which there is twelve times as much carbon as hydrogen. It has not been discovered recently, for it was known early in the nineteenth century, but its possible use for lighting purposes was not considered then.

Attention was directed to it a few years ago by the discovery of a substance called calcium carbide. This is a compound of carbon and the metal calcium, formed by heating to a very high temperature a mixture of coal and lime. It has the peculiar property of decomposing, when treated with water. The calcium present combines with the oxygen and half the hydrogen of the water, to form common slacked lime or calcium hydrate, while the carbon and the remainder of the hydrogen combine to form acetylene gas.

The gas formed in this way needs no purifications before burning; it can be produced in small generators, and the production can be checked at any time. When burned in the proper form of burner it yields the brightest of all gas flames. For these reasons it is adapted for use in small villages and for lighting single houses. It is also frequently used in magic lanterns, where a strong and steady light is necessary. But the cost of producing acetylene in large quantities is greater than that of coal gas, and it seems extremely unlikely that it will ever be much used for lighting large cities and towns.

How the Light Gets Into the Electric Light Bulb.

The incandescent lamp was invented in 1879 and the patents were granted to Thomas A. Edison. There were, however, a number of electrical men who were working on the idea at this time who deserve a great deal of credit for developing the lamp.

The incandescent lamp, which is used chiefly for house lighting, consists of a glass bulb from which the air has been exhausted by pumps and chemical processes—in which there is a thin filament of tungsten metal wound on what is called an arbor (as shown in Fig. 4). This filament opposes high resistance to the passage of the current of electricity, and, consequently, is heated to incandescence when a current passes through it. The removal of the air from the bulb prevents the tungsten metal from burning up, as it would do if oxygen were present.

The filaments of the first lamps were made of vegetable fibre. The next development was the cellulose process, which is still used in carbon and metallized lamps, although a number of processes are used now which improve the filament considerably.

The discovery that tungsten metal could be used in incandescent lamps was made in 1906. The first tungsten lamp manufactured in America was made in 1907.

The filaments of the first tungsten lamps were composed of two or three short pieces of wire. In 1910, however, a lamp with a continuous tungsten filament was invented which increased the strength of the lamp wonderfully.

Mazda is a trade name given to all metal filament lamps made by the prominent American lamp manufacturers.

The reason that the Mazda lamp is so much more efficient than the carbon filament lamp is because the tungsten filament can be burned at a much higher temperature than the present carbon filament, without seriously blackening the bulb.

How Does an Arc Light Burn?

In the arc light a current of electricity is made to leap across from the tip of one rod of carbon to the tip of another that is held a short distance from the first. In passing across the current does not follow a straight path, but makes a curve, or arc, whence comes the name “arc light.”

In this form of light the carbons are not enclosed in a space from which air is excluded, consequently there is some destruction of the carbon. The light is due to the fact that the air between the tips of the carbon rods opposes a high degree of resistance to the current, so that the rods become intensely hot at their tips. The high degree of heat causes a slow burning of the carbon at the tips, and the small particles that burn are heated white hot before they are consumed, thus producing light.

In order to keep the light from an arc light uniform in strength, it is necessary to keep the tips of the carbon rods always the same distance apart. This is practically impossible, and, as a result, the arc light does not produce light that is well adapted for reading or for other purposes that require constant use of the eyes. The light produced by the arc light is very powerful, however, and for that reason it is much used for street lighting.

What Are X-Rays?

It was discovered by Professor Conrad Roentgen in 1895, that if a current of electricity be passed through a certain form of glass bulb, from which most of the air has been exhausted, a disturbance is produced in the ether that bears some resemblance to light waves. For want of a better name to give to a disturbance which was not well understood, Roentgen called his discovery the X-Ray, but it is now frequently called in his honor the Roentgen ray. The nature of this disturbance is not yet known, but as it does not affect the eye it is not light. These rays are produced with a glass vacuum tube and a battery from which a current of electricity is sent through the tube. The wires of the battery are connected with two electrodes, one of which consists of a concave disk of aluminum, and the latter of a flat disk of platinum. The X-rays are discharged in straight lines as shown in the figure. The most striking properties of the X-ray is its power to penetrate many substances that are impermeable to light. All vegetable substances, and the flesh of animals, are penetrated by it very readily. Glass, metals, bones, and mineral substances generally are opaque to it. Consequently, when a limb, or even the body of an animal, is exposed to X-rays they pass through the fleshy parts, but are stopped by the bones. Certain substances have the property of glowing, or becoming fluorescent, when exposed to the X-ray, and when screens of paper are coated with these substances they form a convenient means of detecting the presence of X-rays. By holding the hand between a tube that is giving off X-rays and a screen of this kind, the bones of the hand will be outlined in shadow on the screen, and the rest of the surface will glow with a greenish light. If a bullet or other piece of metal has become imbedded in the body, it may easily be located, if it is not in a bone, and the extent of an injury to a bone or a joint may be plainly shown. For this reason the X-ray is now widely used by surgeons.

How Man Learned to Fight Fire.

When you see the modern fire engine racing through the streets, gongs ringing, with the firemen hanging on and the police clearing the track, you should remember that it has taken man a long time to learn as much as he has about fighting fire.

No sooner did man learn to make fire than he found it necessary to learn how to put it out.

The first fire apparatus of record is found in Rome. The Gauls burned the city in 390 B. C., each citizen was ordered to keep in his house a “machine for extinguishing fire.” This consisted of a syringe.

The first record of an actual machine for putting out fire is by Hero of Alexandria. This contrivance, a “siphon used in conflagrations,” was used in Egypt about a hundred and fifty years before Christ.

The first record of what we would call a fire department is also found in Rome. A disastrous fire, occurring in the reign of Augustus called his attention to the benefit of a regular fire brigade would bring. So he organized a fire department. It consisted of seven companies of a thousand men each.

The first real fire engines were used in 1633 at a big fire on London Bridge. The first fire hose was invented by the two Van der Heydes in 1672. One of the earliest engines used consisted of a tank drawn by two horses, which threw a stream an inch in diameter to a height of eighty feet. An improved engine was invented in 1721 by Newsham, of London, and the first engine used in the United States was made by Newsham. The first steam fire engine was invented by John Braithwaite, of London, in 1829.

Fire alarms came into use in medieval times. It was the custom, in many of the towns to have a watchman stationed on a high building whose duty it was to look for fires. As soon as he saw one, he gave warning by blowing a horn, firing a gun, or ringing a bell.

The first London fire department consisted of ten men of each ward.

The first municipal American fire department was created in Boston in 1678. The fire engine was a hand pump bought in England.

The first leather fire hose was made in America in 1808 in Philadelphia. Rubber hose was first made in England at about 1820.

How Did Man Learn to Cook His Food?

The primitive man lived on raw food—raw flesh, roots, fruits and nuts. There must have been a time when he lived thus because there was a time when he had no fires and no knowledge of how to make a fire. There are no records, however, to show when man learned that cooked food was best.

It must have come about almost simultaneously with his knowledge of fire, for the art of cooking goes back to the first knowledge of fire. We do not know either how man learned to make a fire. The earliest nations of which we have any record seem to have been acquainted with fire and certain methods for producing it. Not only one but all early nations seem to have been possessed of this knowledge. Occasionally travellers have reported that people have been found who were unacquainted with either fire or cooking, but investigation has always proven these reports unauthentic. Cookery has always been found in practice where people knew about fire.

It is strange how man has lost track of the beginning of his knowledge of fire and cookery, because fire represents the beginning of man’s culture and cookery goes hand in hand with it.

There are many legendary accounts of how man learned the value of cooked food, all of which are based upon the accidental burning or roasting of animals or birds. Perhaps, therefore, Charles Lamb’s “Roast Pig” story, which we read with much laughter in our school readers, was quite accurate from a historical standpoint. According to the story a man’s house burned and he cried more over the fate of his pet pig than about the loss of his house. He kept his pig in the house you will remember and as soon as the fire died away he rushed into the debris to look for his pet pig, hoping still to rescue him. He found him in a corner and made haste to pick him up and carry him into the open air. But the poor pig had been roasted to a turn and was still hot. The man’s fingers went right into the well done roast pig and were burned. With a cry he withdrew his fingers and put them into his mouth to blow on them and thus he secured his first taste of roast pig, which he found so much to his taste that he repeated the operation of licking his fingers.

While this is but a story, it is quite likely historically correct as to this discovery of the value of cooked food to some of the early nations. No doubt Fire and Cookery were developed together.

When man had learned to make fire, he found that it often got beyond his control. Here and there he would set the woods on fire quite without intention perhaps, but with damaging results. He would watch the conflagration and, when it was passed, he would find the baked bodies of deer or other animals which had been overcome by the fire and learned that baked meats were good to the taste and more easily digestible than raw meats.

Why Does a Sponge Hold Water?

A sponge will hold water because it has, on account of the plan on which it is grown the power of capillary attraction. The sponge is made up of little hair like tubes. If you take a glass tube, open at both ends and immerse one end in a vessel of water, you will find that the water will rise in the tube to a level higher than the surface of the water in the vessel. The smaller the hole through the glass tube, the higher the water will rise. This is caused by the cohesion of the water against the inside surface of the hole in the tube and causes a pull upward. The water is pulled up into the tube because the surface of the tube has a greater cohesive attraction for the water than for the air which was in it and the air is forced out partly. Some liquids, such as mercury will not rise in the same way, but is depressed in a glass tube, since it cannot adhere to glass. Mercury however will run or rise in a tin tube, just as water in a glass tube, because it adheres to the tin.

Now a sponge is merely a lot of capillary tubes which have the same power of pulling up the water as the glass tube. The tubes in a sponge are so fine that the water will rise to the entire length of the tubes. In addition, this adhesive quality of water to the inside of the tubes in the sponge is so strong, that the sponge can be taken entirely out of the water and the water will remain in it.

Why Is the Right Hand Stronger Than the Left?

The right hand is stronger than the left only in case you are right-handed. If you have the habit of being left-handed, your left hand becomes stronger. If you are truly ambidextrous, your strength will be the same in both hands.

We get our strength by moving the various parts of the body, i. e., by using them. When a little baby stretches his arms and legs and kicks, he is only exercising naturally, making the blood circulate.

You can prove that the fact that your right hand is stronger than your left because of the greater use or exercise you give it, by tying your right arm close to your side and keeping it in that condition without using it for several weeks. When you remove the bands which held it tight, you will find your arm has lost its strength and that now your left hand is stronger. If, however, you are left-handed and tie that hand down for the same length of time, your right hand would be the stronger. This shows that the strength we have in our arms and legs, and other parts of the body, is developed by using them and giving them rational exercise. Of course, it is possible to over-use a part of the body, but you will notice that nature always gives us a warning by making us tired before we come to the point where further use of that particular part of the body would cause injury.

Why Do My Muscles Get Sore When I Play Ball In the Spring?

They do this because you have probably not been exercising the particular muscles which you employ in throwing a ball enough in the winter to keep you in good condition. Muscles which have been developed through use or work need more work to keep them in condition. In a sense certain of the muscles which you employ in playing ball have been treated during the winter very much as if you had tied them down, as we suggested you might do with your arm. You have not been using them—they have not been doing enough work, and they begin to lose their strength when for any period they have not been used enough. The soreness that you feel is the natural condition that arises when you begin to use a muscle that has been idle for some time.

Why Does a Barber’s Pole Have Stripes?

In early years the barber not only cut hair and shaved people, but he was also a surgeon. He was a surgeon to the extent that he bled people. In early times our knowledge of surgery was practically limited to blood letting. A great many of the ailments were attributed to too much blood in the body, and when anything got wrong with a man or woman, the first thing they thought of was to reduce the amount of blood in the body by taking some of it out.

The town barber was the man who did this for people and his pole represented the sign of his business.

The round ball at the top which was generally gilded represents the barbering end of the business. It stood for the brass basin which the barber used to prepare lather for shaving customers.

The pole itself represents the staff which people who were having blood taken out of their bodies held during the operation. The two spiral ribbons, one red and one white, which are painted spirally on the pole, represented the bandages. The white one stood for the bandage which was put on before the blood was taken out and the red one the bandage which was used for binding up the wound when the operation was completed.

How Was the Flag Made?

The design of our flag was outlined in a congressional resolution passed on June 14, 1777, which stated “that the flag of the thirteen United States be thirteen alternate stripes red and white; that the union be thirteen stars, white in a blue field, representing the new constellation.” After Vermont and Kentucky had been admitted to the Union, Congress made a decree in 1794 that after May 1, 1795, “the flag of the United States be fifteen stripes alternate red and white and that the Union be fifteen stars white on a blue field.” This made the stars and stripes again equal and it was the plan to add a new stripe and a new star for each new state admitted to the Union. Very soon, however, it was realized that the flag would be too large if we kept on adding one stripe for each new state admitted to the Union, so on April 4, 1818, Congress passed a resolution reducing the number of stripes to thirteen once more to represent the original colonies, and to add only a new star to the field when a new state was admitted to the Union. At this time there were twenty states in the Union. Since that time none of the flags of the United States have more than thirteen stripes while a new star has been added for each state until now we have forty-eight stars, representing the forty-eight states.

Why Are Some Guns Called Gatling Guns?

A gatling gun is a kind of gun invented by Richard Jordan Gatling in 1861 and 1862 and so it receives its name from its inventor. The original gatling gun had ten parallel barrels and was capable of firing 1,000 shots per minute when operated by hand power. It was discharged by turning a crank and would shoot in proportion to the rapidity with which the crank was turned. It was at first not a huge success but has from time to time been improved so that the crank is now turned by electric power and about fifteen hundred shots per minute can be fired with it.

How Did Hobson’s Choice Originate?

As used today, this expression means a choice with only one thing to choose. Tobias Hobson was a livery stable keeper at Cambridge, England, during the reign of King Charles I. He kept a stable of forty horses which he hired out by the hour or day, and was famous in his day so far as a livery stable keeper could be.

When you went to Hobson to hire a horse, you had the privilege of looking over all the horses in the stable to decide which one you would like to drive, but he always made you take the one in the stall nearest the door. In this way all the horses in the stable were worked in turn and while you might pretend to choose your own horse, you really had no choice—you had to take the one nearest the door or none. As soon as a horse was hired, the other horses in the stable were moved up, each one to the stall next towards the door so there was always a horse in the stall nearest the door.

Why Do They Call It a Honeymoon?

The word Honeymoon which is commonly used to describe the first few weeks after marriage, has always meant the first month or moon after marriage, but does not have any reference to the month or moon excepting as that describes a certain period of time.

The word originated in an old custom quite common among newly married couples among the ancient Teutons of drinking a kind of wine made from honey during the first thirty days after being married.

In these days newly married couples generally take a trip away from home for a short or longer period after their wedding day and this is called the honeymoon whether it is but a few days or three months or more. The custom of drinking wine made from honey has been abandoned so that the word is now used in an entirely different sense than formerly.

Why Is a Horseshoe Said to Bring Good Luck?

The luck of the horseshoe comes from three lucky things always connected with horseshoes. These consist of the following facts: It is the shape of a crescent; it is a portion of a horse; it is made of iron.

Each of these has from time immemorial been considered lucky. Anything in the shape of a crescent was always considered a thing to bring luck. From the earliest times, too, at least since the world knew something of the qualities of iron, iron has been regarded as a thing to give protection and incidentally that would involve good luck. And lastly the horse, since the days of English mythology, has been regarded as a luck animal. When, then, we had a combination of the three—the crescent, the iron and the horse in one object, it became a true lucky sign in the eyes of the people.